Split ch10

Basic memory introduction in 10a, then precise aliases in 10b.

56 files changed, 0 insertions, 8974 deletions

diff --git a/chapter10/src/main/java/com/seaofnodes/simple/IRPrinter.java b/chapter10/src/main/java/com/seaofnodes/simple/IRPrinter.java
deleted file mode 100644
index 1ac32b1a..00000000
--- a/chapter10/src/main/java/com/seaofnodes/simple/IRPrinter.java
+++ /dev/null
@@ -1,188 +0,0 @@
-package com.seaofnodes.simple;
-
-import com.seaofnodes.simple.node.LoopNode;
-import com.seaofnodes.simple.node.Node;
-import com.seaofnodes.simple.node.ProjNode;
-
-import java.util.ArrayList;
-import java.util.BitSet;
-
-public class IRPrinter {
-
-    // Print a node on 1 line, columnar aligned, as:
-    // NNID NNAME DDEF DDEF  [[  UUSE UUSE  ]]  TYPE
-    // 1234 sssss 1234 1234 1234 1234 1234 1234 tttttt
-    public static void _printLine( Node n, StringBuilder sb ) {
-        sb.append("%4d %-7.7s ".formatted(n._nid,n.label()));
-        if( n.isDead() ) {
-            sb.append("DEAD\n");
-            return;
-        }
-        for( Node def : n._inputs )
-            sb.append(def==null ? "____ " : "%4d ".formatted(def._nid));
-        for( int i = n._inputs.size(); i<3; i++ )
-            sb.append("     ");
-        sb.append(" [[  ");
-        for( Node use : n._outputs )
-            sb.append(use==null ? "____ " : "%4d ".formatted(use._nid));
-        int lim = 5 - Math.max(n._inputs.size(),3);
-        for( int i = n._outputs.size(); i<lim; i++ )
-            sb.append("     ");
-        sb.append(" ]]  ");
-        if( n._type!= null ) sb.append(n._type.str());
-        sb.append("\n");
-    }
-
-    private static StringBuilder nodeId(StringBuilder sb, Node n) {
-        sb.append("%%%d".formatted(n._nid));
-        if (n instanceof ProjNode proj) {
-            sb.append(".").append(proj._idx);
-        }
-        return sb;
-    }
-
-    // Print a node on 1 line, format is inspired by LLVM
-    // %id: TYPE = NODE(inputs ....)
-    // Nodes as referred to as %id
-    public static void _printLineLlvmFormat( Node n, StringBuilder sb ) {
-        nodeId(sb, n).append(": ");
-        if( n.isDead() ) {
-            sb.append("DEAD\n");
-            return;
-        }
-        if( n._type!= null ) n._type.typeName(sb);
-        sb.append(" = ").append( n.label() ).append( "(" );
-        for( int i = 0; i < n._inputs.size(); i++ ) {
-            Node def = n.in(i);
-            if (i > 0)
-                sb.append(", ");
-            if (def == null) sb.append("_");
-            else             nodeId(sb, def);
-        }
-        sb.append(")").append("\n");
-    }
-
-    public static void printLine( Node n, StringBuilder sb, boolean llvmFormat ) {
-        if (llvmFormat) _printLineLlvmFormat( n, sb );
-        else            _printLine          ( n, sb );
-    }
-
-    public static String prettyPrint(Node node, int depth) {
-        return prettyPrint( node, depth, false );
-    }
-
-    // Another bulk pretty-printer.  Makes more effort at basic-block grouping.
-    public static String prettyPrint( Node node, int depth, boolean llvmFormat ) {
-        // First, a Breadth First Search at a fixed depth.
-        BFS bfs = new BFS(node,depth);
-        // Convert just that set to a post-order
-        ArrayList<Node> rpos = new ArrayList<>();
-        BitSet visit = new BitSet();
-        for( int i=bfs._lim; i< bfs._bfs.size(); i++ )
-            postOrd( bfs._bfs.get(i), rpos, visit, bfs._bs);
-        // Reverse the post-order walk
-        StringBuilder sb = new StringBuilder();
-        boolean gap=false;
-        for( int i=rpos.size()-1; i>=0; i-- ) {
-            Node n = rpos.get(i);
-            if( n.isCFG() || n.isMultiHead() ) {
-                if( !gap ) sb.append("\n"); // Blank before multihead
-                printLine( n, sb, llvmFormat ); // Print head
-                while( --i >= 0 ) {
-                    Node t = rpos.get(i);
-                    if( !t.isMultiTail() ) { i++; break; }
-                    printLine( t, sb, llvmFormat );
-                }
-                sb.append("\n"); // Blank after multitail
-                gap = true;
-            } else {
-                printLine( n, sb, llvmFormat );
-                gap = false;
-            }
-        }
-        return sb.toString();
-    }
-
-    private static void postOrd(Node n, ArrayList<Node> rpos, BitSet visit, BitSet bfs) {
-        if( !bfs.get(n._nid) )
-            return;  // Not in the BFS visit
-        if( visit.get(n._nid) ) return; // Already post-order walked
-        visit.set(n._nid);
-        // First walk the CFG, then everything
-        if( n.isCFG() ) {
-            for( Node use : n._outputs )
-                if( use!=null && use.isCFG() && use.nOuts()>=1 && !(use._outputs.get(0) instanceof LoopNode) )
-                    postOrd(use, rpos,visit,bfs);
-            for( Node use : n._outputs )
-                if( use!=null && use.isCFG() )
-                    postOrd(use,rpos,visit,bfs);
-        }
-        for( Node use : n._outputs )
-            if( use != null )
-                postOrd(use, rpos,visit,bfs);
-        // Post-order
-        rpos.add(n);
-    }
-
-    // Breadth-first search, broken out in a class to keep in more independent.
-    // Maintains a root-set of Nodes at the limit (or past by 1 if MultiHead).
-    public static class BFS {
-        // A breadth first search, plus MultiHeads for any MultiTails
-        public final ArrayList<Node> _bfs;
-        public final BitSet _bs; // Visited members by node id
-        public final int _depth; // Depth limit
-        public final int _lim; // From here to _bfs._len can be roots for a reverse search
-        public BFS( Node base, int d ) {
-            _depth = d;
-            _bfs = new ArrayList<>();
-            _bs = new BitSet();
-
-            add(base);                 // Prime the pump
-            int idx=0, lim=1;          // Limit is where depth counter changes
-            while( idx < _bfs.size() ) { // Ran out of nodes below depth
-                Node n = _bfs.get(idx++);
-                for( Node def : n._inputs )
-                    if( def!=null && !_bs.get(def._nid) )
-                        add(def);
-                if( idx==lim ) {    // Depth counter changes at limit
-                    if( --d < 0 )
-                        break;      // Ran out of depth
-                    lim = _bfs.size();  // New depth limit
-                }
-            }
-            // Toss things past the limit except multi-heads
-            while( idx < _bfs.size() ) {
-                Node n = _bfs.get(idx);
-                if( n.isMultiHead() ) idx++;
-                else del(idx);
-            }
-            // Root set is any node with no inputs in the visited set
-            lim = _bfs.size();
-            for( int i=_bfs.size()-1; i>=0; i-- )
-                if( !any_visited(_bfs.get(i)) )
-                    swap( i,--lim);
-            _lim = lim;
-        }
-        void swap( int x, int y ) {
-            if( x==y ) return;
-            Node tx = _bfs.get(x);
-            Node ty = _bfs.get(y);
-            _bfs.set(x,ty);
-            _bfs.set(y,tx);
-        }
-        void add(Node n) {
-            _bfs.add(n);
-            _bs.set(n._nid);
-        }
-        void del(int idx) {
-            Node n = Utils.del(_bfs, idx);
-            _bs.clear(n._nid);
-        }
-        boolean any_visited( Node n ) {
-            for( Node def : n._inputs )
-                if( def!=null && _bs.get(def._nid) )
-                    return true;
-            return false;
-        }
-    }
-}
diff --git a/chapter10/src/main/java/com/seaofnodes/simple/IterPeeps.java b/chapter10/src/main/java/com/seaofnodes/simple/IterPeeps.java
deleted file mode 100644
index 7075d526..00000000
--- a/chapter10/src/main/java/com/seaofnodes/simple/IterPeeps.java
+++ /dev/null
@@ -1,208 +0,0 @@
-package com.seaofnodes.simple;
-
-import com.seaofnodes.simple.node.*;
-
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.BitSet;
-import java.util.Random;
-
-/**
- * The IterOptim runs after parsing. It iterates the peepholes to a fixed point
- * so that no more peepholes apply.  This should be linear because peepholes rarely
- * (never?)  increase code size.  The graph should monotonically reduce in some
- * dimension, which is usually size.  It might also reduce in e.g. number of
- * MulNodes or Load/Store nodes, swapping out more "expensive" Nodes for cheaper
- * ones.
- *
- * The theoretical overall worklist is mindless just grabbing the next thing and
- * doing it.  If the graph changes, put the neighbors on the worklist.  Lather,
- * Rinse, Repeat until the worklist runs dry.
- *
- * The main issues we have to deal with:
- *
- * <ul>
- * <li>Nodes have uses; replacing some set of Nodes with another requires more graph
- *   reworking.  Not rocket science, but it can be fiddly.  Its helpful to have a
- *   small set of graph munging utilities, and the strong invariant that the graph
- *   is stable and correct between peepholes.  In our case `Node.subsume` does
- *   most of the munging, building on our prior stable Node utilities.</li>
- *
- * <li>Changing a Node also changes the graph "neighborhood".  The neigbors need to
- *   be checked to see if THEY can also peephole, and so on.  After any peephole
- *   or graph update we put a Nodes uses and defs on the worklist.</li>
- *
- * <li>Our strong invariant is that for all Nodes, either they are on the worklist
- *   OR no peephole applies.  This invariant is easy to check, although expensive.
- *   Basically the normal "iterate peepholes to a fixed point" is linear, and this
- *   check is linear at each peephole step... so quadratic overall.  Its a useful
- *   assert, but one we can disable once the overall algorithm is stable - and
- *   then turn it back on again when some new set of peepholes is misbehaving.
- *   The code for this is turned on in `IterOptim.iterate` as `assert
- *   progressOnList(stop);`</li>
- * </ul>
- */
-public abstract class IterPeeps {
-
-    private static final WorkList<Node> WORK = new WorkList<>();
-
-    public static <N extends Node> N add( N n ) {
-        return (N)WORK.push(n);
-    }
-
-    public static void addAll( ArrayList<Node> ary ) {
-        WORK.addAll(ary);
-    }
-
-    /**
-     * Iterate peepholes to a fixed point
-     */
-    public static StopNode iterate(StopNode stop) {
-        assert progressOnList(stop);
-        int cnt=0;
-
-        Node n;
-        while( (n=WORK.pop()) != null ) {
-            if( n.isDead() )  continue;
-            cnt++;              // Useful for debugging, searching which peephole broke things
-            var obs = Parser.PARSER == null ? null : Parser.PARSER._obs;
-            if( obs != null ) obs.before(n);
-            Node x = n.peepholeOpt();
-            if( x != null ) {
-                if( x.isDead() ) {
-                    if( obs != null ) obs.after(n, x, true);
-                    continue;
-                }
-                // peepholeOpt can return brand-new nodes, needing an initial type set
-                if( x._type==null ) x.setType(x.compute());
-                // Changes require neighbors onto the worklist
-                if( x != n || !(x instanceof ConstantNode) ) {
-                    // All outputs of n (changing node) not x (prior existing node).
-                    for( Node z : n._outputs ) WORK.push(z);
-                    // Everybody gets a free "go again" in case they didn't get
-                    // made in their final form.
-                    WORK.push(x);
-                    // If the result is not self, revisit all inputs (because
-                    // there's a new user), and replace in the graph.
-                    if( x != n ) {
-                        for( Node z : n. _inputs ) WORK.push(z);
-                        n.subsume(x);
-                    }
-                }
-                // If there are distant neighbors, move to worklist
-                n.moveDepsToWorklist();
-                assert progressOnList(stop); // Very expensive assert
-            }
-            if( n.isUnused() && !(n instanceof StopNode) )
-                n.kill();       // Just plain dead
-            if( obs != null ) obs.after(n, x, true);
-        }
-
-        return stop;
-    }
-
-    // Visit ALL nodes and confirm the invariant:
-    //   Either you are on the WORK worklist OR running `iter()` makes no progress.
-
-    // This invariant ensures that no progress is missed, i.e., when the
-    // worklist is empty we have indeed done all that can be done.  To help
-    // with debugging, the {@code assert} is broken out in a place where it is easy to
-    // stop if a change is found.
-
-    // Also, the normal usage of `iter()` may attempt peepholes with distance
-    // neighbors and these should fail, but will then try to add dependencies
-    // {@link #Node.addDep} which is a side effect in an assert.  The {@link
-    // #midAssert} is used to stop this side effect.
-    private static boolean MID_ASSERT;
-    public static boolean midAssert() { return MID_ASSERT; }
-    private static boolean progressOnList(Node stop) {
-        MID_ASSERT = true;
-        int old_cnt = Node.ITER_CNT, old_nop = Node.ITER_NOP_CNT;
-        Node changed = stop.walk( n -> {
-                if( WORK.on(n) ) return null;
-                Node m = n.peepholeOpt();
-                if( m==null ) return null;
-                System.err.println("BREAK HERE FOR BUG");
-                return m;
-            });
-        Node.ITER_CNT = old_cnt;  Node.ITER_NOP_CNT = old_nop;
-        MID_ASSERT = false;
-        return changed==null;
-    }
-
-    public static void reset() {
-        WORK.clear();
-    }
-
-    /**
-     * Classic WorkList, with a fast add/remove, dup removal, random pull.
-     * The Node's nid is used to check membership in the worklist.
-     */
-    public static class WorkList<E extends Node> {
-
-        private Node[] _es;
-        private int _len;
-        private final BitSet _on;   // Bit set if Node._nid is on WorkList
-        private final Random _R;    // For randomizing pull from the WorkList
-        private final long _seed;
-
-        /* Useful stat - how many nodes are processed in the post parse iterative opt */
-        private long _totalWork = 0;
-
-        WorkList() { this(123); }
-        WorkList(long seed) {
-            _es = new Node[1];
-            _len=0;
-            _on = new BitSet();
-            _seed = seed;
-            _R = new Random();
-            _R.setSeed(_seed);
-        }
-
-        /**
-         * Pushes a Node on the WorkList, ensuring no duplicates
-         * If Node is null it will not be added.
-         */
-        public E push( E x ) {
-            if( x==null ) return null;
-            int idx = x._nid;
-            if( !_on.get(idx) ) {
-                _on.set(idx);
-                if( _len==_es.length )
-                    _es = Arrays.copyOf(_es,_len<<1);
-                _es[_len++] = x;
-                _totalWork++;
-            }
-            return x;
-        }
-
-        public void addAll( ArrayList<E> ary ) {
-            for( E n : ary )
-                push(n);
-        }
-
-        /**
-         * True if Node is on the WorkList
-         */
-        boolean on( E x ) { return _on.get(x._nid); }
-
-        /**
-         * Removes a random Node from the WorkList; null if WorkList is empty
-         */
-        E pop() {
-            if( _len == 0 ) return null;
-            int idx = _R.nextInt(_len);
-            E x = (E)_es[idx];
-            _es[idx] = _es[--_len]; // Compress array
-            _on.clear(x._nid);
-            return x;
-        }
-
-        public void clear() {
-            _len = 0;
-            _on.clear();
-            _R.setSeed(_seed);
-            _totalWork = 0;
-        }
-    }
-}
diff --git a/chapter10/src/main/java/com/seaofnodes/simple/Parser.java b/chapter10/src/main/java/com/seaofnodes/simple/Parser.java
deleted file mode 100644
index ddbbdf82..00000000
--- a/chapter10/src/main/java/com/seaofnodes/simple/Parser.java
+++ /dev/null
@@ -1,834 +0,0 @@
-package com.seaofnodes.simple;
-
-import com.seaofnodes.graph.GraphObserver;
-
-import com.seaofnodes.simple.node.*;
-import com.seaofnodes.simple.type.*;
-
-import java.util.*;
-
-/**
- * The Parser converts a Simple source program to the Sea of Nodes intermediate
- * representation directly in one pass. There is no intermediate Abstract
- * Syntax Tree structure.
- * <p>
- * This is a simple recursive descent parser. All lexical analysis is done here as well.
- */
-public class Parser {
-
-    // Current compilation context; the observer belongs to the parser.
-    public static Parser PARSER;
-    public GraphObserver<Node> _obs;
-    public int pos() { return _lexer._position; }
-
-
-    /**
-     * A Global Static, unique to each compilation.  This is a public, so we
-     * can make constants everywhere without having to thread the StartNode
-     * through the entire parser and optimizer.
-     * <p>
-     * To make the compiler multithreaded, this field will have to move into a TLS.
-     */
-    public static StartNode START;
-
-    public StopNode STOP;
-
-    // The Lexer.  Thin wrapper over a byte[] buffer with a cursor.
-    private final Lexer _lexer;
-
-    /**
-     * Current ScopeNode - ScopeNodes change as we parse code, but at any point of time
-     * there is one current ScopeNode. The reason the current ScopeNode can change is to do with how
-     * we handle branching. See {@link #parseIf()}.
-     * <p>
-     * Each ScopeNode contains a stack of lexical scopes, each scope is a symbol table that binds
-     * variable names to Nodes.  The top of this stack represents current scope.
-     * <p>
-     * We keep a list of all ScopeNodes so that we can show them in graphs.
-     * @see #parseIf()
-     * @see #_xScopes
-     */
-    public ScopeNode _scope;
-
-    /**
-     * List of keywords disallowed as identifiers
-     */
-    private static final HashSet<String> KEYWORDS = new HashSet<>(){{
-            add("break");
-            add("continue");
-            add("else");
-            add("false");
-            add("if");
-            add("int");
-            add("new");
-            add("null");
-            add("return");
-            add("struct");
-            add("true");
-            add("while");
-        }};
-
-
-    /**
-     * We clone ScopeNodes when control flows branch; it is useful to have
-     * a list of all active ScopeNodes for purposes of visualization of the SoN graph
-     */
-    public final Stack<ScopeNode> _xScopes = new Stack<>();
-
-    ScopeNode _continueScope;
-    ScopeNode _breakScope;
-
-    // Mapping from a Struct name to a Struct.
-    public static Map<String, TypeStruct> OBJS = new HashMap<>();
-
-    public Parser(String source, TypeInteger arg) {
-        PARSER = this;
-        Node.reset();
-        IterPeeps.reset();
-        OBJS.clear();
-        _lexer = new Lexer(source);
-        _scope = new ScopeNode();
-        _continueScope = _breakScope = null;
-        START = new StartNode(new Type[]{ Type.CONTROL, arg });
-        STOP = new StopNode(source);
-    }
-
-    public Parser(String source) {
-        this(source, TypeInteger.BOT);
-    }
-
-    @Override
-    public String toString() { return _lexer.toString(); }
-
-    String src() { return new String( _lexer._input ); }
-
-    // Debugging utility to find a Node by index
-    public static Node find(int nid) { return START.find(nid); }
-
-    private Node ctrl() { return _scope.ctrl(); }
-
-    private Node ctrl(Node n) { return _scope.ctrl(n); }
-
-    public StopNode parse() {
-        _xScopes.push(_scope);
-        // Enter a new scope for the initial control and arguments
-        _scope.push();
-        _scope.define(ScopeNode.CTRL, Type.CONTROL   , new ProjNode(START, 0, ScopeNode.CTRL).peephole());
-        _scope.define(ScopeNode.ARG0, TypeInteger.BOT, new ProjNode(START, 1, ScopeNode.ARG0).peephole());
-        parseBlock();
-        _scope.pop();
-        _xScopes.pop();
-        if (!_lexer.isEOF()) throw error("Syntax error, unexpected " + _lexer.getAnyNextToken());
-        STOP.peephole();
-        return STOP;
-    }
-
-    /**
-     * Parses a block
-     *
-     * <pre>
-     *     '{' statements '}'
-     * </pre>
-     * Does not parse the opening or closing '{}'
-     * @return a {@link Node} or {@code null}
-     */
-    private Node parseBlock() {
-        // Enter a new scope
-        _scope.push();
-        while (!peek('}') && !_lexer.isEOF())
-            parseStatement();
-        // Exit scope
-        _scope.pop();
-        return null;
-    }
-
-    /**
-     * Parses a statement
-     *
-     * <pre>
-     *     returnStatement | declStatement | blockStatement | ifStatement | expressionStatement
-     * </pre>
-     * @return a {@link Node} or {@code null}
-     */
-    private Node parseStatement() {
-        if( false ) return null;
-        else if (matchx("return")  ) return parseReturn();
-        else if (matchx("int")     ) return parseDecl(TypeInteger.BOT);
-        else if (match ("{")       ) return require(parseBlock(),"}");
-        else if (matchx("if")      ) return parseIf();
-        else if (matchx("while")   ) return parseWhile();
-        else if (matchx("break")   ) return parseBreak();
-        else if (matchx("continue")) return parseContinue();
-        else if (matchx("struct")  ) return parseStruct();
-        else if (matchx(";")       ) return null; // Empty statement
-        // declarations of vars with struct type are handled in parseExpressionStatement due
-        // to ambiguity
-        else return parseExpressionStatement();
-    }
-
-    /**
-     * Parse a struct field.
-     * <pre>
-     *     int IDENTIFIER ;
-     * </pre>
-     */
-    private Field parseField(String sname) {
-        if( matchx("int") )     // Currently only parsing "int" type fields
-            return require(Field.make(requireId().intern(),TypeInteger.BOT),";");
-        throw errorSyntax("A field type is expected, only type 'int' is supported at present");
-    }
-
-    /**
-     * Parse a struct declaration, and return the following statement.
-     * Only allowed in top level scope.
-     * Structs cannot be redefined.
-     *
-     * @return The statement following the struct
-     */
-    private Node parseStruct() {
-        if (_xScopes.size() > 1) throw errorSyntax("struct declarations can only appear in top level scope");
-        String typeName = requireId();
-        if ( OBJS.containsKey(typeName)) throw errorSyntax("struct '" + typeName + "' cannot be redefined");
-        ArrayList<Field> fields = new ArrayList<>();
-        require("{");
-        while (!peek('}') && !_lexer.isEOF()) {
-            Field field = parseField(typeName);
-            if (fields.contains(field)) throw errorSyntax("Field '" + field + "' already defined in struct '" + typeName + "'");
-            fields.add(field);
-        }
-        require("}");
-        // Build and install the TypeStruct
-        TypeStruct ts = TypeStruct.make(typeName, fields);
-        OBJS.put(typeName, ts); // Insert the struct name in the collection of all struct names
-        START.addMemProj(ts, _scope); // Insert memory edges
-        return parseStatement();
-    }
-
-    /**
-     * Parses a while statement
-     *
-     * <pre>
-     *     while ( expression ) statement
-     * </pre>
-     * @return a {@link Node}, never {@code null}
-     */
-    private Node parseWhile() {
-
-        var savedContinueScope = _continueScope;
-        var savedBreakScope    = _breakScope;
-
-        require("(");
-
-        // Loop region has two control inputs, the first is the entry
-        // point, and second is back edge that is set after loop is parsed
-        // (see end_loop() call below).  Note that the absence of back edge is
-        // used as an indicator to switch off peepholes of the region and
-        // associated phis; see {@code inProgress()}.
-
-        ctrl(new LoopNode(ctrl()).peephole()); // Note we set back edge to null here
-
-        // At loop head, we clone the current Scope (this includes all
-        // names in every nesting level within the Scope).
-        // We create phis eagerly for all the names we find, see dup().
-
-        // Save the current scope as the loop head
-        ScopeNode head = _scope.keep();
-        // Clone the head Scope to create a new Scope for the body.
-        // Create phis eagerly as part of cloning
-        _xScopes.push(_scope = _scope.dup(true)); // The true argument triggers creating phis
-
-        // Parse predicate
-        var pred = require(parseExpression(), ")");
-        // IfNode takes current control and predicate
-        Node ifNode = new IfNode(ctrl(), pred).peephole();
-        // Setup projection nodes
-        Node ifT = new ProjNode(ifNode.  keep(), 0, "True" ).peephole().keep();
-        Node ifF = new ProjNode(ifNode.unkeep(), 1, "False").peephole();
-
-        // Clone the body Scope to create the break/exit Scope which accounts for any
-        // side effects in the predicate.  The break/exit Scope will be the final
-        // scope after the loop, and its control input is the False branch of
-        // the loop predicate.  Note that body Scope is still our current scope.
-        ctrl(ifF);
-        _xScopes.push(_breakScope = _scope.dup());
-
-        // No continues yet
-        _continueScope = null;
-
-        // Parse the true side, which corresponds to loop body
-        // Our current scope is the body Scope
-        ctrl(ifT.unkeep());     // set ctrl token to ifTrue projection
-        parseStatement();       // Parse loop body
-
-        // Merge the loop bottom into other continue statements
-        if (_continueScope != null) {
-            _continueScope = jumpTo(_continueScope);
-            _scope.kill();
-            _scope = _continueScope;
-        }
-
-        // The true branch loops back, so whatever is current _scope.ctrl gets
-        // added to head loop as input.  endLoop() updates the head scope, and
-        // goes through all the phis that were created earlier.  For each phi,
-        // it sets the second input to the corresponding input from the back
-        // edge.  If the phi is redundant, it is replaced by its sole input.
-        var exit = _breakScope;
-        head.endLoop(_scope, exit);
-        head.unkeep().kill();
-
-        _xScopes.pop();       // Cleanup
-        _xScopes.pop();       // Cleanup
-
-        _continueScope = savedContinueScope;
-        _breakScope = savedBreakScope;
-
-        // At exit the false control is the current control, and
-        // the scope is the exit scope after the exit test.
-        return _scope = exit;
-    }
-
-    private ScopeNode jumpTo(ScopeNode toScope) {
-        ScopeNode cur = _scope.dup();
-        ctrl(new ConstantNode(Type.XCONTROL).peephole()); // Kill current scope
-        // Prune nested lexical scopes that have depth > than the loop head
-        // We use _breakScope as a proxy for the loop head scope to obtain the depth
-        while( cur._scopes.size() > _breakScope._scopes.size() )
-            cur.pop();
-        // If this is a continue then first time the target is null
-        // So we just use the pruned current scope as the base for the
-        // "continue"
-        if (toScope == null)
-            return cur;
-        // toScope is either the break scope, or a scope that was created here
-        assert toScope._scopes.size() <= _breakScope._scopes.size();
-        toScope.ctrl(toScope.mergeScopes(cur));
-        return toScope;
-    }
-
-    private void checkLoopActive() { if (_breakScope == null) throw Parser.error("No active loop for a break or continue"); }
-
-    private Node parseBreak   () { checkLoopActive(); return (   _breakScope = require(jumpTo(    _breakScope ),";"));  }
-    private Node parseContinue() { checkLoopActive(); return (_continueScope = require(jumpTo( _continueScope ),";"));  }
-
-    /**
-     * Parses a statement
-     *
-     * <pre>
-     *     if ( expression ) statement [else statement]
-     * </pre>
-     * @return a {@link Node}, never {@code null}
-     */
-    private Node parseIf() {
-        require("(");
-        // Parse predicate
-        var pred = require(parseExpression(), ")").keep();
-        // IfNode takes current control and predicate
-        Node ifNode = new IfNode(ctrl(), pred).peephole();
-        // Setup projection nodes
-        Node ifT = new ProjNode(ifNode.  keep(), 0, "True" ).peephole().keep();
-        Node ifF = new ProjNode(ifNode.unkeep(), 1, "False").peephole().keep();
-        // In if true branch, the ifT proj node becomes the ctrl
-        // But first clone the scope and set it as current
-        int ndefs = _scope.nIns();
-        ScopeNode fScope = _scope.dup(); // Duplicate current scope
-        fScope.ctrl(ifF);       // The pending arm already starts at False
-        _xScopes.push(fScope); // For graph visualization we need all scopes
-
-        // Parse the true side
-        ctrl(ifT.unkeep());     // set ctrl token to ifTrue projection
-        _scope.upcast(ifT,pred,false); // Up-cast predicate
-        parseStatement();       // Parse true-side
-        ScopeNode tScope = _scope;
-
-        // Parse the false side
-        _scope = fScope;        // Restore scope, then parse else block if any
-        ifF.unkeep();           // fScope already owns the false control
-        if (matchx("else")) {
-            _scope.upcast(ifF,pred,true); // Up-cast predicate
-            parseStatement();
-            fScope = _scope;
-        }
-        pred.unkeep();
-
-        if( tScope.nIns() != ndefs || fScope.nIns() != ndefs )
-            throw error("Cannot define a new name on one arm of an if");
-
-        // Merge results
-        _scope = tScope;
-        _xScopes.pop();       // Discard pushed from graph display
-
-        return ctrl(tScope.mergeScopes(fScope));
-    }
-
-
-    /**
-     * Parses a return statement; "return" already parsed.
-     * The $ctrl edge is killed.
-     *
-     * <pre>
-     *     'return' expr ;
-     * </pre>
-     * @return an expression {@link Node}, never {@code null}
-     */
-    private Node parseReturn() {
-        var expr = require(parseExpression(), ";");
-        Node ret = STOP.addReturn(new ReturnNode(ctrl(), expr, _scope).peephole());
-        ctrl(new ConstantNode(Type.XCONTROL).peephole()); // Kill control
-        return ret;
-    }
-
-
-
-    /**
-     * Parses an expression statement or a declaration statement where type is a struct
-     *
-     * <pre>
-     *      name;         // Error
-     * type name;         // Define name with default initial value
-     * type name = expr;  // Define name with given   initial value
-     *      name = expr;  // Reassign existing
-     *             expr   // Something else
-     * </pre>
-     * @return an expression {@link Node}, never {@code null}
-     */
-    private Node parseExpressionStatement() {
-        int old = _lexer._position;
-        Type t = type();
-        String name = requireId();
-        Node expr;
-        if( match(";") ) {      // Assign a default value
-            // No type and no expr is an error
-            if( t==null ) throw errorSyntax("expression");
-            expr = new ConstantNode(t.makeInit()).peephole();
-        } else if( match("=") ) { // Assign "= expr;"
-            expr = require(parseExpression(), ";");
-        } else {                // Neither, so just a normal expression parse
-            _lexer._position = old;
-            return require(parseExpression(),";");
-        }
-
-        // Defining a new variable vs updating an old one
-        if( t != null ) {
-            if( _scope.define(name,t,expr) == null )
-                throw error("Redefining name '" + name + "'");
-        } else {
-            Node n = _scope.lookup(name);
-            t = _scope.lookupDeclaredType(name);
-            if( n==null )
-                throw error("Undefined name '" + name + "'");
-            _scope.update(name,expr);
-        }
-        if( !expr._type.isa(t) )
-            throw error("Type " + expr._type.str() + " is not of declared type " + t.str());
-        return expr;
-    }
-
-    // Parse a type-or-null
-    private Type type() {
-        int old = _lexer._position;
-        String tname = _lexer.matchId();
-        if( tname==null ) return null;
-        if( tname.equals("int") ) return TypeInteger.BOT;
-        TypeStruct obj = OBJS.get(tname);
-        if( obj != null )
-            return TypeMemPtr.make(obj,match("?"));
-        // Not a type; unwind the parse
-        _lexer._position = old;
-        return null;
-    }
-
-    /**
-     * Parses a declStatement
-     *
-     * <pre>
-     *     type name = expression ';'
-     * </pre>
-     * @return an expression {@link Node}
-     */
-    private Node parseDecl(Type t) {
-        var name = requireId();
-        var expr = match(";")
-            // Assign a null value
-            ? new ConstantNode(t.makeInit()).peephole()
-            // Assign "= expr;"
-            : require(require("=").parseExpression(), ";");
-        if( !expr._type.isa(t) )
-            throw error("Type " + expr._type.str() + " is not of declared type " + t.str());
-        if( _scope.define(name,t,expr) == null )
-            throw error("Redefining name '" + name + "'");
-        return expr;
-    }
-
-
-    /**
-     * Parse an expression of the form:
-     *
-     * <pre>
-     *     expr : compareExpr
-     * </pre>
-     * @return an expression {@link Node}, never {@code null}
-     */
-    private Node parseExpression() { return parseComparison(); }
-
-    /**
-     * Parse an expression of the form:
-     *
-     * <pre>
-     *     expr : additiveExpr op additiveExpr
-     * </pre>
-     * @return an comparator expression {@link Node}, never {@code null}
-     */
-    private Node parseComparison() {
-        var lhs = parseAddition();
-        while( true ) {
-            int idx=0;  boolean negate=false;
-            // Test for any local nodes made, and "keep" lhs during peepholes
-            if( false ) ;
-            else if( match("==") ) { idx=2;  lhs = new BoolNode.EQ(lhs, null); }
-            else if( match("!=") ) { idx=2;  lhs = new BoolNode.EQ(lhs, null); negate=true; }
-            else if( match("<=") ) { idx=2;  lhs = new BoolNode.LE(lhs, null); }
-            else if( match("<" ) ) { idx=2;  lhs = new BoolNode.LT(lhs, null); }
-            else if( match(">=") ) { idx=1;  lhs = new BoolNode.LE(null, lhs); }
-            else if( match(">" ) ) { idx=1;  lhs = new BoolNode.LT(null, lhs); }
-            else break;
-            // Peepholes can fire, but lhs is already "hooked", kept alive
-            lhs.setDef(idx,parseAddition());
-            lhs = lhs.peephole();
-            if( negate )        // Extra negate for !=
-                lhs = new NotNode(lhs).peephole();
-        }
-        return lhs;
-    }
-
-    /**
-     * Parse an additive expression
-     *
-     * <pre>
-     *     additiveExpr : multiplicativeExpr (('+' | '-') multiplicativeExpr)*
-     * </pre>
-     * @return an add expression {@link Node}, never {@code null}
-     */
-    private Node parseAddition() {
-        Node lhs = parseMultiplication();
-        while( true ) {
-            if( false ) ;
-            else if( match("+") ) lhs = new AddNode(lhs,null);
-            else if( match("-") ) lhs = new SubNode(lhs,null);
-            else break;
-            lhs.setDef(2,parseMultiplication());
-            lhs = lhs.peephole();
-        }
-        return lhs;
-    }
-
-    /**
-     * Parse an multiplicativeExpr expression
-     *
-     * <pre>
-     *     multiplicativeExpr : unaryExpr (('*' | '/') unaryExpr)*
-     * </pre>
-     * @return a multiply expression {@link Node}, never {@code null}
-     */
-    private Node parseMultiplication() {
-        var lhs = parseUnary();
-        while( true ) {
-            if( false ) ;
-            else if( match("*") ) lhs = new MulNode(lhs,null);
-            else if( match("/") ) lhs = new DivNode(lhs,null);
-            else break;
-            lhs.setDef(2,parseUnary());
-            lhs = lhs.peephole();
-        }
-        return lhs;
-    }
-
-    /**
-     * Parse a unary minus expression.
-     *
-     * <pre>
-     *     unaryExpr : ('-') | '!') unaryExpr | postfixExpr | primaryExpr
-     * </pre>
-     * @return a unary expression {@link Node}, never {@code null}
-     */
-    private Node parseUnary() {
-        if (match("-")) return new MinusNode(parseUnary()).peephole();
-        if (match("!")) return new   NotNode(parseUnary()).peephole();
-        return parsePostfix(parsePrimary());
-    }
-
-    /**
-     * Parse a primary expression:
-     *
-     * <pre>
-     *     primaryExpr : integerLiteral | Identifier | true | false | null | new Identifier | '(' expression ')'
-     * </pre>
-     * @return a primary {@link Node}, never {@code null}
-     */
-    private Node parsePrimary() {
-        if( _lexer.isNumber() ) return parseIntegerLiteral();
-        if( match("(") ) return require(parseExpression(), ")");
-        if( matchx("true" ) ) return new ConstantNode(TypeInteger.constant(1)).peephole();
-        if( matchx("false") ) return new ConstantNode(TypeInteger.constant(0)).peephole();
-        if( matchx("null" ) ) return new ConstantNode(TypeMemPtr.NULLPTR).peephole();
-        if( matchx("new") ) {
-            String structName = requireId();
-            TypeStruct obj = OBJS.get(structName);
-            if( obj == null) throw errorSyntax("Unknown struct type '" + structName + "'");
-            return newStruct(obj);
-        }
-        String name = _lexer.matchId();
-        if( name == null) throw errorSyntax("an identifier or expression");
-        Node n = _scope.lookup(name);
-        if( n!=null ) return n;
-        throw error("Undefined name '" + name + "'");
-    }
-
-    /**
-     * Return a NewNode but also generate instructions to initialize it.
-     */
-    private Node newStruct( TypeStruct obj ) {
-        Node n = new NewNode(TypeMemPtr.make(obj), ctrl()).peephole().keep();
-        Node initValue = new ConstantNode(TypeInteger.constant(0)).peephole();
-        int alias = START._aliasStarts.get(obj._name);
-        for( Field field : obj._fields ) {
-            memAlias(alias, new StoreNode(field._fname, alias, memAlias(alias), n, initValue).peephole());
-            alias++;
-        }
-        return n.unkeep();
-    }
-
-    // We set up memory aliases by inserting special vars in the scope these
-    // variables are prefixed by $ so they cannot be referenced in Simple code.
-    // Using vars has the benefit that all the existing machinery of scoping
-    // and phis work as expected
-    private Node memAlias(int alias         ) { return _scope.lookup(memName(alias)    ); }
-    private Node memAlias(int alias, Node st) { return _scope.update(memName(alias), st); }
-    public static String memName(int alias) { return ("$"+alias).intern(); }
-
-    /**
-     * Parse postfix expression. For now this is just a field
-     * expression, but in future could be array index too.
-     *
-     * <pre>
-     *     expr ('.' IDENTIFIER)* [ = expr ]
-     * </pre>
-     */
-    private Node parsePostfix(Node expr) {
-        if( !match(".") ) return expr;
-
-        if( !(expr._type instanceof TypeMemPtr ptr) )
-            throw error("Expected struct reference but got " + expr._type.str());
-
-        String name = requireId().intern();
-        int idx = ptr._obj==null ? -1 : ptr._obj.find(name);
-        if( idx == -1 ) throw error("Accessing unknown field '" + name + "' from '" + ptr.str() + "'");
-        int alias = START._aliasStarts.get(ptr._obj._name)+idx;
-
-        if( match("=") ) {
-            // Disambiguate "obj.fld==x" boolean test from "obj.fld=x" field assignment
-            if( peek('=') ) _lexer._position--;
-            else {
-                Node val = parseExpression();
-                memAlias(alias, new StoreNode(name, alias, memAlias(alias), expr, val).peephole());
-                return expr;        // "obj.a = expr" returns the expression while updating memory
-            }
-        }
-
-        Type declaredType = ptr._obj._fields[idx]._type;
-        return parsePostfix(new LoadNode(name, alias, declaredType, memAlias(alias), expr).peephole());
-    }
-
-    /**
-     * Parse integer literal
-     *
-     * <pre>
-     *     integerLiteral: [1-9][0-9]* | [0]
-     * </pre>
-     */
-    private ConstantNode parseIntegerLiteral() {
-        return (ConstantNode) new ConstantNode(_lexer.parseNumber()).peephole();
-    }
-
-    //////////////////////////////////
-    // Utilities for lexical analysis
-
-    // Return true and skip if "syntax" is next in the stream.
-    private boolean match (String syntax) { return _lexer.match (syntax); }
-    // Match must be "exact", not be followed by more id letters
-    private boolean matchx(String syntax) { return _lexer.matchx(syntax); }
-    // Return true and do NOT skip if 'ch' is next
-    private boolean peek(char ch) { return _lexer.peek(ch); }
-    private boolean peekIsId() { return _lexer.peekIsId(); }
-
-    // Require and return an identifier
-    private String requireId() {
-        String id = _lexer.matchId();
-        if (id != null && !KEYWORDS.contains(id) ) return id;
-        throw error("Expected an identifier, found '"+id+"'");
-    }
-
-
-
-    // Require an exact match
-    private Parser require(String syntax) { require(null, syntax); return this; }
-    private <N> N require(N n, String syntax) {
-        if (match(syntax)) return n;
-        throw errorSyntax(syntax);
-    }
-
-    RuntimeException errorSyntax(String syntax) {
-        return error("Syntax error, expected " + syntax + ": " + _lexer.getAnyNextToken());
-    }
-
-    public static RuntimeException error( String errorMessage ) {
-        return new RuntimeException(errorMessage);
-    }
-
-    ////////////////////////////////////
-    // Lexer components
-
-    private static class Lexer {
-
-        // Input buffer; an array of text bytes read from a file or a string
-        private final byte[] _input;
-        // Tracks current position in input buffer
-        private int _position = 0;
-
-        /**
-         * Record the source text for lexing
-         */
-        public Lexer(String source) {
-            this(source.getBytes());
-        }
-
-        /**
-         * Direct from disk file source
-         */
-        public Lexer(byte[] buf) {
-            _input = buf;
-        }
-
-        // Very handy in the debugger, shows the unparsed program
-        @Override
-        public String toString() {
-            return new String(_input, _position, _input.length - _position);
-        }
-
-        // True if at EOF
-        private boolean isEOF() {
-            return _position >= _input.length;
-        }
-
-        // Peek next character, or report EOF
-        private char peek() {
-            return isEOF() ? Character.MAX_VALUE   // Special value that causes parsing to terminate
-                    : (char) _input[_position];
-        }
-
-        private char nextChar() {
-            char ch = peek();
-            _position++;
-            return ch;
-        }
-
-        // True if a white space
-        private boolean isWhiteSpace() {
-            return peek() <= ' '; // Includes all the use space, tab, newline, CR
-        }
-
-        /**
-         * Return the next non-white-space character
-         */
-        private void skipWhiteSpace() {
-            while (isWhiteSpace()) _position++;
-        }
-
-
-        // Return true, if we find "syntax" after skipping white space; also
-        // then advance the cursor past syntax.
-        // Return false otherwise, and do not advance the cursor.
-        boolean match(String syntax) {
-            skipWhiteSpace();
-            int len = syntax.length();
-            if (_position + len > _input.length) return false;
-            for (int i = 0; i < len; i++)
-                if ((char) _input[_position + i] != syntax.charAt(i))
-                    return false;
-            _position += len;
-            return true;
-        }
-
-        // Match must be exact and not followed by more ID characters.
-        // Prevents identifier "ifxy" from matching an "if" statement.
-        boolean matchx(String syntax) {
-            if( !match(syntax) ) return false;
-            if( !isIdLetter(peek()) ) return true;
-            _position -= syntax.length();
-            return false;
-        }
-
-        private boolean peek(char ch) {
-            skipWhiteSpace();
-            return peek()==ch;
-        }
-
-        boolean peekIsId() {
-            skipWhiteSpace();
-            return isIdStart(peek());
-        }
-
-        // Return an identifier or null
-        String matchId() {
-            return peekIsId() ? parseId() : null;
-        }
-
-        // Used for errors
-        String getAnyNextToken() {
-            if (isEOF()) return "";
-            if (isIdStart(peek())) return parseId();
-            if (isNumber(peek())) return parseNumberString();
-            if (isPunctuation(peek())) return parsePunctuation();
-            return String.valueOf(peek());
-        }
-
-        boolean isNumber() {return isNumber(peek());}
-        boolean isNumber(char ch) {return Character.isDigit(ch);}
-
-        private Type parseNumber() {
-            String snum = parseNumberString();
-            if (snum.length() > 1 && snum.charAt(0) == '0')
-                throw error("Syntax error: integer values cannot start with '0'");
-            return TypeInteger.constant(Long.parseLong(snum));
-        }
-        private String parseNumberString() {
-            int start = _position;
-            while (isNumber(nextChar())) ;
-            return new String(_input, start, --_position - start);
-        }
-
-        // First letter of an identifier
-        private boolean isIdStart(char ch) {
-            return Character.isAlphabetic(ch) || ch == '_';
-        }
-
-        // All characters of an identifier, e.g. "_x123"
-        private boolean isIdLetter(char ch) {
-            return Character.isLetterOrDigit(ch) || ch == '_';
-        }
-
-        private String parseId() {
-            int start = _position;
-            while (isIdLetter(nextChar())) ;
-            return new String(_input, start, --_position - start);
-        }
-
-        private boolean isPunctuation(char ch) {
-            return "=;[]<>(){}+-/*!".indexOf(ch) != -1;
-        }
-
-        private String parsePunctuation() {
-            int start = _position;
-            return new String(_input, start, 1);
-        }
-    }
-}
diff --git a/chapter10/src/main/java/com/seaofnodes/simple/Utils.java b/chapter10/src/main/java/com/seaofnodes/simple/Utils.java
deleted file mode 100644
index 4f2af769..00000000
--- a/chapter10/src/main/java/com/seaofnodes/simple/Utils.java
+++ /dev/null
@@ -1,65 +0,0 @@
-package com.seaofnodes.simple;
-
-import java.util.ArrayList;
-
-public class Utils {
-    public static RuntimeException TODO() { return TODO("Not yet implemented"); }
-    public static RuntimeException TODO(String msg) { return new RuntimeException(msg); }
-
-    /**
-     *  Fast, constant-time, element removal.  Does not preserve order
-     *
-     *  @param array ArrayList to modify
-     *  @param i element to be removed
-     *  @return element removed
-     */
-    public static <E> E del(ArrayList<E> array, int i) {
-        if ( i >= 0 && i < array.size() ) {
-            E tmp = array.get(i);
-            E last = array.removeLast();
-            if (i < array.size()) array.set(i, last);
-            return tmp;
-        }
-        return null;
-    }
-
-    /**
-     * Search a list for an element by reference
-     *
-     * @param ary List to search in
-     * @param x Object to be searched
-     * @return >= 0 on success, -1 on failure
-     */
-    public static <E> int find( ArrayList<E> ary, E x ) {
-        for( int i=0; i<ary.size(); i++ )
-            if( ary.get(i)==x )
-                return i;
-        return -1;
-    }
-    /**
-     * Search a list for an element by reference
-     *
-     * @param ary List to search in
-     * @param x Object to be searched
-     * @return >= 0 on success, -1 on failure
-     */
-    public static <E> int find( E[] ary, E x ) {
-        for( int i=0; i<ary.length; i++ )
-            if( ary[i]==x )
-                return i;
-        return -1;
-    }
-
-    // Rotate a long, nice for hashes
-    public static long rot( long x, int n ) { return (x<<n) | (x>>>n); }
-
-    // Fold a 64bit hash into 32 bits
-    public static int fold( long x ) { return (int)((x>>32) ^ x); }
-
-    public static boolean eq(String s0, String s1) {
-        if( s0==s1 ) return true;
-        assert s0==s0.intern();
-        assert s1==s1.intern();
-        return false;
-    }
-}
diff --git a/chapter10/src/main/java/com/seaofnodes/simple/node/AddNode.java b/chapter10/src/main/java/com/seaofnodes/simple/node/AddNode.java
deleted file mode 100644
index de5044d7..00000000
--- a/chapter10/src/main/java/com/seaofnodes/simple/node/AddNode.java
+++ /dev/null
@@ -1,176 +0,0 @@
-package com.seaofnodes.simple.node;
-
-import com.seaofnodes.simple.type.*;
-
-import java.util.BitSet;
-
-public class AddNode extends Node {
-    public AddNode(Node lhs, Node rhs) { super(null, lhs, rhs); }
-
-    @Override public String label() { return "Add"; }
-
-    @Override
-    StringBuilder _print1(StringBuilder sb, BitSet visited) {
-        in(1)._print0(sb.append("("), visited);
-        in(2)._print0(sb.append("+"), visited);
-        return sb.append(")");
-    }
-
-
-    @Override
-    public Type compute() {
-        Type t1 = in(1)._type, t2 = in(2)._type;
-        if( t1==Type.TOP || t1==TypeInteger.TOP ||
-            t2==Type.TOP || t2==TypeInteger.TOP )
-            return TypeInteger.TOP;
-        if( t1 instanceof TypeInteger i0 &&
-            t2 instanceof TypeInteger i1 ) {
-            if (i0.isConstant() && i1.isConstant())
-                return TypeInteger.constant(i0.value()+i1.value());
-        }
-        return TypeInteger.BOT;
-    }
-
-    @Override
-    public Node idealize () {
-        Node lhs = in(1);
-        Node rhs = in(2);
-        Type t2 = rhs._type;
-
-        // Add of 0.  We do not check for (0+x) because this will already
-        // canonicalize to (x+0)
-        if( t2 instanceof TypeInteger i && i.value()==0 )
-            return lhs;
-
-        // Add of same to a multiply by 2
-        if( lhs==rhs )
-            return new MulNode(lhs,new ConstantNode(TypeInteger.constant(2)).peephole());
-
-        // Goal: a left-spine set of adds, with constants on the rhs (which then fold).
-
-        // Move non-adds to RHS
-        if( !(lhs instanceof AddNode) && rhs instanceof AddNode )
-            return swap12();
-
-        // x+(-y) becomes x-y
-        if( rhs instanceof MinusNode minus )
-            return new SubNode(lhs,minus.in(1));
-
-        // Now we might see (add add non) or (add non non) or (add add add) but never (add non add)
-
-        // Do we have  x + (y + z) ?
-        // Swap to    (x + y) + z
-        // Rotate (add add add) to remove the add on RHS
-        if( rhs instanceof AddNode add )
-            return new AddNode(new AddNode(lhs,add.in(1)).peephole(), add.in(2));
-
-        // Now we might see (add add non) or (add non non) but never (add non add) nor (add add add)
-        if( !(lhs instanceof AddNode) )
-            // Rotate; look for (add (phi cons) con/(phi cons))
-            return spine_cmp(lhs,rhs,this) ? swap12() : phiCon(this,true);
-
-        // Now we only see (add add non)
-
-        // Dead data cycle; comes about from dead infinite loops.  Do nothing,
-        // the loop will peep as dead after a bit.
-        if( lhs.in(1) == lhs )
-            return null;
-
-        // Do we have (x + con1) + con2?
-        // Replace with (x + (con1+con2) which then fold the constants
-        // lhs.in(2) is con1 here
-        // If lhs.in(2) is not a constant, we add ourselves as a dependency
-        // because if it later became a constant then we could make this
-        // transformation.
-        if( lhs.in(2).addDep(this)._type.isConstant() && rhs._type.isConstant() )
-            return new AddNode(lhs.in(1),new AddNode(lhs.in(2),rhs).peephole());
-
-
-        // Do we have ((x + (phi cons)) + con) ?
-        // Do we have ((x + (phi cons)) + (phi cons)) ?
-        // Push constant up through the phi: x + (phi con0+con0 con1+con1...)
-        Node phicon = phiCon(this,true);
-        if( phicon!=null ) return phicon;
-
-        // Now we sort along the spine via rotates, to gather similar things together.
-
-        // Do we rotate (x + y) + z
-        // into         (x + z) + y ?
-        if( spine_cmp(lhs.in(2),rhs,this) )
-            return new AddNode(new AddNode(lhs.in(1),rhs).peephole(),lhs.in(2));
-
-        return null;
-    }
-
-    // Rotation is only valid for associative ops, e.g. Add, Mul, And, Or.
-    // Do we have ((phi cons)|(x + (phi cons)) + con|(phi cons)) ?
-    // Push constant up through the phi: x + (phi con0+con0 con1+con1...)
-    static Node phiCon(Node op, boolean rotate) {
-        Node lhs = op.in(1);
-        Node rhs = op.in(2);
-        // LHS is either a Phi of constants, or another op with Phi of constants
-        PhiNode lphi = pcon(lhs,op);
-        if( rotate && lphi==null && lhs.nIns() > 2 ) {
-            // Only valid to rotate constants if both are same associative ops
-            if( lhs.getClass() != op.getClass() ) return null;
-            lphi = pcon(lhs.in(2),op); // Will rotate with the Phi push
-        }
-        if( lphi==null ) return null;
-
-        // RHS is a constant or a Phi of constants
-        if( !(rhs instanceof ConstantNode) && pcon(rhs,op)==null )
-            return null;
-
-        // If both are Phis, must be same Region
-        if( rhs instanceof PhiNode && lphi.in(0) != rhs.in(0) )
-            return null;
-
-        // Note that this is the exact reverse of Phi pulling a common op down
-        // to reduce total op-count.  We don't get in an endless push-up
-        // push-down peephole cycle because the constants all fold first.
-        Node[] ns = new Node[lphi.nIns()];
-        ns[0] = lphi.in(0);
-        // Push constant up through the phi: x + (phi con0+con0 con1+con1...)
-        for( int i=1; i<ns.length; i++ )
-            ns[i] = op.copy(lphi.in(i), rhs instanceof PhiNode ? rhs.in(i) : rhs).peephole();
-        String label = lphi._label + (rhs instanceof PhiNode rphi ? rphi._label : "");
-        Node phi = new PhiNode(label,lphi._declaredType,ns).peephole();
-        // Rotate needs another op, otherwise just the phi
-        return lhs==lphi ? phi : op.copy(lhs.in(1),phi);
-    }
-
-    /**
-     * Tests if the op is a phi and has all constant inputs.
-     * If not, returns null.
-     * If op is a phi, but its inputs are not all constants, then dep is added as
-     * a dependency to the phi's non-const input, because if later the input turn into a constant
-     * dep can make progress.
-     */
-    static PhiNode pcon(Node op, Node dep) {
-        return op instanceof PhiNode phi && phi.allCons(dep) ? phi : null;
-    }
-
-    // Compare two off-spine nodes and decide what order they should be in.
-    // Do we rotate ((x + hi) + lo) into ((x + lo) + hi) ?
-    // Generally constants always go right, then Phi-of-constants, then muls, then others.
-    // Ties with in a category sort by node ID.
-    // TRUE if swapping hi and lo.
-    static boolean spine_cmp( Node hi, Node lo, Node dep ) {
-        if( lo._type.isConstant() ) return false;
-        if( hi._type.isConstant() ) return true ;
-
-        if( lo instanceof PhiNode lphi && lphi.region()._type==Type.XCONTROL ) return false;
-        if( hi instanceof PhiNode hphi && hphi.region()._type==Type.XCONTROL ) return false;
-
-        if( lo instanceof PhiNode && lo.allCons(dep) ) return false;
-        if( hi instanceof PhiNode && hi.allCons(dep) ) return true ;
-
-        if( lo instanceof PhiNode && !(hi instanceof PhiNode) ) return true;
-        if( hi instanceof PhiNode && !(lo instanceof PhiNode) ) return false;
-
-        // Same category of "others"
-        return lo._nid > hi._nid;
-    }
-
-    @Override Node copy(Node lhs, Node rhs) { return new AddNode(lhs,rhs); }
-}
diff --git a/chapter10/src/main/java/com/seaofnodes/simple/node/BoolNode.java b/chapter10/src/main/java/com/seaofnodes/simple/node/BoolNode.java
deleted file mode 100644
index bf0d3a84..00000000
--- a/chapter10/src/main/java/com/seaofnodes/simple/node/BoolNode.java
+++ /dev/null
@@ -1,76 +0,0 @@
-package com.seaofnodes.simple.node;
-
-import com.seaofnodes.simple.type.Type;
-import com.seaofnodes.simple.type.TypeInteger;
-import com.seaofnodes.simple.type.TypeMemPtr;
-
-import java.util.BitSet;
-
-abstract public class BoolNode extends Node {
-
-    public BoolNode(Node lhs, Node rhs) {
-        super(null, lhs, rhs);
-    }
-
-    abstract String op();       // String opcode name
-
-    @Override
-    public String label() { return getClass().getSimpleName(); }
-
-    @Override
-    StringBuilder _print1(StringBuilder sb, BitSet visited) {
-        in(1)._print0(sb.append("("), visited);
-        in(2)._print0(sb.append(op()), visited);
-        return sb.append(")");
-    }
-
-    @Override
-    public Type compute() {
-        Type t1 = in(1)._type, t2 = in(2)._type;
-        if( t1==Type.TOP || t1==TypeInteger.TOP ||
-            t2==Type.TOP || t2==TypeInteger.TOP )
-            return TypeInteger.TOP;
-        if( t1 instanceof TypeInteger i0 &&
-            t2 instanceof TypeInteger i1 ) {
-            if (i0.isConstant() && i1.isConstant())
-                return TypeInteger.constant(doOp(i0.value(), i1.value()) ? 1 : 0);
-        }
-        return TypeInteger.BOT;
-    }
-
-    abstract boolean doOp(long lhs, long rhs);
-
-    @Override
-    public Node idealize() {
-        // Compare of same
-        if( in(1)==in(2) )
-            return new ConstantNode(TypeInteger.constant(doOp(3,3)?1:0));
-
-        // Equals pushes constant to the right; 5==X becomes X==5.
-        if( this instanceof EQ ) {
-            if( !(in(2) instanceof ConstantNode) ) {
-                // con==noncon becomes noncon==con
-                if( in(1) instanceof ConstantNode )
-                    return new EQ(in(2),in(1));
-                // Equals sorts by NID otherwise: non.high == non.low becomes non.low == non.high
-                else if( in(1)._nid > in(2)._nid )
-                    return new EQ(in(2),in(1));
-            }
-            // Equals X==0 becomes a !X
-            if( (in(2)._type == TypeInteger.ZERO || in(2)._type == TypeMemPtr.NULLPTR) )
-                return new NotNode(in(1));
-        }
-
-        // Do we have ((phi cons) cmp con) ?
-        // Do we have ((phi cons) cmp (phi cons)) ?
-        // Push the compare up through the phi: (phi con0 cmp con, con1 cmp con...)
-        Node phicon = AddNode.phiCon(this,this instanceof EQ);
-        if( phicon!=null ) return phicon;
-
-        return null;
-    }
-
-    public static class EQ extends BoolNode { public EQ(Node lhs, Node rhs) { super(lhs,rhs); } String op() { return "=="; } boolean doOp(long lhs, long rhs) { return lhs == rhs; } Node copy(Node lhs, Node rhs) { return new EQ(lhs,rhs); } }
-    public static class LT extends BoolNode { public LT(Node lhs, Node rhs) { super(lhs,rhs); } String op() { return "<" ; } boolean doOp(long lhs, long rhs) { return lhs <  rhs; } Node copy(Node lhs, Node rhs) { return new LT(lhs,rhs); } }
-    public static class LE extends BoolNode { public LE(Node lhs, Node rhs) { super(lhs,rhs); } String op() { return "<="; } boolean doOp(long lhs, long rhs) { return lhs <= rhs; } Node copy(Node lhs, Node rhs) { return new LE(lhs,rhs); } }
-}
diff --git a/chapter10/src/main/java/com/seaofnodes/simple/node/CastNode.java b/chapter10/src/main/java/com/seaofnodes/simple/node/CastNode.java
deleted file mode 100644
index fec540f7..00000000
--- a/chapter10/src/main/java/com/seaofnodes/simple/node/CastNode.java
+++ /dev/null
@@ -1,38 +0,0 @@
-package com.seaofnodes.simple.node;
-
-import com.seaofnodes.simple.type.Type;
-import com.seaofnodes.simple.type.TypeInteger;
-import com.seaofnodes.simple.IterPeeps;
-
-import java.util.BitSet;
-
-// Upcast (join) the input to a t.  Used after guard test to lift an input.
-// Can also be used to make a type-assertion if ctrl is null.
-public class CastNode extends Node {
-    private final Type _t;
-    public CastNode(Type t, Node ctrl, Node in) {
-        super(ctrl, in);
-        _t = t;
-        setType(compute());
-    }
-
-    @Override public String label() { return "("+_t.str()+")"; }
-
-    @Override
-    public String uniqueName() { return "Cast_" + _nid; }
-
-    @Override
-    StringBuilder _print1(StringBuilder sb, BitSet visited) {
-        return in(1)._print0(sb.append(label()), visited);
-    }
-
-    @Override
-    public Type compute() {
-        return in(1)._type.join(_t);
-    }
-
-    @Override
-    public Node idealize() {
-        return in(1)._type.isa(_t) ? in(1) : null;
-    }
-}
diff --git a/chapter10/src/main/java/com/seaofnodes/simple/node/ConstantNode.java b/chapter10/src/main/java/com/seaofnodes/simple/node/ConstantNode.java
deleted file mode 100644
index d760c0df..00000000
--- a/chapter10/src/main/java/com/seaofnodes/simple/node/ConstantNode.java
+++ /dev/null
@@ -1,54 +0,0 @@
-package com.seaofnodes.simple.node;
-
-import com.seaofnodes.simple.Parser;
-import com.seaofnodes.simple.type.Type;
-
-import java.util.BitSet;
-
-/**
- * A Constant node represents a constant value.  At present, the only constants
- * that we allow are integer literals; therefore Constants contain an integer
- * value.  As we add other types of constants, we will refactor how we represent
- * Constants.
- * <p>
- * Constants have no semantic inputs. However, we set Start as an input to
- * Constants to enable a forward graph walk.  This edge carries no semantic
- * meaning, and it is present <em>solely</em> to allow visitation.
- * <p>
- * The Constant's value is the value stored in it.
- */
-public class ConstantNode extends Node {
-    final Type _con;
-    public ConstantNode( Type type ) {
-        super(Parser.START);
-        _con = type;
-    }
-
-    @Override
-    public String label() { return "#"+_con; }
-
-    @Override
-    public String uniqueName() { return "Con_" + _nid; }
-
-    @Override
-    StringBuilder _print1(StringBuilder sb, BitSet visited) {
-        return _con.print(sb);
-    }
-
-    @Override public boolean isMultiTail() { return true; }
-
-    @Override
-    public Type compute() { return _con; }
-
-    @Override
-    public Node idealize() { return null; }
-
-    @Override
-    boolean eq(Node n) {
-        ConstantNode con = (ConstantNode)n; // Contract
-        return _con==con._con;
-    }
-
-    @Override
-    int hash() { return _con.hashCode(); }
-}
diff --git a/chapter10/src/main/java/com/seaofnodes/simple/node/DivNode.java b/chapter10/src/main/java/com/seaofnodes/simple/node/DivNode.java
deleted file mode 100644
index 6cee90ad..00000000
--- a/chapter10/src/main/java/com/seaofnodes/simple/node/DivNode.java
+++ /dev/null
@@ -1,45 +0,0 @@
-package com.seaofnodes.simple.node;
-
-import com.seaofnodes.simple.type.Type;
-import com.seaofnodes.simple.type.TypeInteger;
-
-import java.util.BitSet;
-
-public class DivNode extends Node {
-    public DivNode(Node lhs, Node rhs) { super(null, lhs, rhs); }
-
-    @Override public String label() { return "Div"; }
-
-    @Override
-    StringBuilder _print1(StringBuilder sb, BitSet visited) {
-        in(1)._print0(sb.append("("), visited);
-        in(2)._print0(sb.append("/"), visited);
-        return sb.append(")");
-    }
-
-    @Override
-    public Type compute() {
-        Type t1 = in(1)._type, t2 = in(2)._type;
-        if( t1==Type.TOP || t1==TypeInteger.TOP ||
-            t2==Type.TOP || t2==TypeInteger.TOP )
-            return TypeInteger.TOP;
-        if (t1 instanceof TypeInteger i0 &&
-            t2 instanceof TypeInteger i1) {
-            if (i0.isConstant() && i1.isConstant())
-                return i1.value() == 0
-                    ? TypeInteger.ZERO
-                    : TypeInteger.constant(i0.value()/i1.value());
-        }
-        return TypeInteger.BOT;
-    }
-
-    @Override
-    public Node idealize() {
-        // Div of 1.
-        if( in(2)._type.isConstant() && in(2)._type instanceof TypeInteger i && i.value()==1 )
-            return in(1);
-        return null;
-    }
-
-    @Override Node copy(Node lhs, Node rhs) { return new DivNode(lhs,rhs); }
-}
diff --git a/chapter10/src/main/java/com/seaofnodes/simple/node/IfNode.java b/chapter10/src/main/java/com/seaofnodes/simple/node/IfNode.java
deleted file mode 100644
index 1cf4ddaf..00000000
--- a/chapter10/src/main/java/com/seaofnodes/simple/node/IfNode.java
+++ /dev/null
@@ -1,62 +0,0 @@
-package com.seaofnodes.simple.node;
-
-import com.seaofnodes.simple.IterPeeps;
-import com.seaofnodes.simple.type.Type;
-import com.seaofnodes.simple.type.TypeInteger;
-import com.seaofnodes.simple.type.TypeTuple;
-import java.util.BitSet;
-
-public class IfNode extends MultiNode {
-
-    public IfNode(Node ctrl, Node pred) {
-        super(ctrl, pred);
-        IterPeeps.add(this);    // Because idoms are complex, just add it
-    }
-
-    @Override
-    public String label() { return "If"; }
-
-    @Override
-    StringBuilder _print1(StringBuilder sb, BitSet visited) {
-        sb.append("if( ");
-        return in(1)._print0(sb, visited).append(" )");
-    }
-
-    @Override public boolean isCFG() { return true; }
-    @Override public boolean isMultiHead() { return true; }
-
-    public Node ctrl() { return in(0); }
-    public Node pred() { return in(1); }
-
-    @Override
-    public Type compute() {
-        // If the If node is not reachable then neither is any following Proj
-        if (ctrl()._type != Type.CONTROL && ctrl()._type != Type.BOTTOM )
-            return TypeTuple.IF_NEITHER;
-        Node pred = pred();
-        Type t = pred._type;
-        // High types mean NEITHER side is reachable.
-        // Wait until the type falls to decide which way to go.
-        if( t == Type.TOP || t == TypeInteger.TOP )
-            return TypeTuple.IF_NEITHER;
-        // If constant is 0 then false branch is reachable
-        // Else true branch is reachable
-        if (t instanceof TypeInteger ti && ti.isConstant())
-            return ti==TypeInteger.ZERO ? TypeTuple.IF_FALSE : TypeTuple.IF_TRUE;
-
-        return TypeTuple.IF_BOTH;
-    }
-
-    @Override
-    public Node idealize() {
-        // Hunt up the immediate dominator tree.  If we find an identical if
-        // test on either the true or false branch, that side wins.
-        if( !pred()._type.isHighOrConst() )
-            for( Node dom = idom(), prior=this; dom!=null;  prior = dom, dom = dom.idom() )
-                if( dom.addDep(this) instanceof IfNode iff && iff.pred().addDep(this)==pred() && prior instanceof ProjNode prj ) {
-                    setDef(1,new ConstantNode(TypeInteger.make(true,prj._idx==0?1:0)).peephole());
-                    return this;
-                }
-        return null;
-    }
-}
diff --git a/chapter10/src/main/java/com/seaofnodes/simple/node/LoadNode.java b/chapter10/src/main/java/com/seaofnodes/simple/node/LoadNode.java
deleted file mode 100644
index ece27d86..00000000
--- a/chapter10/src/main/java/com/seaofnodes/simple/node/LoadNode.java
+++ /dev/null
@@ -1,75 +0,0 @@
-package com.seaofnodes.simple.node;
-
-import com.seaofnodes.simple.Utils;
-import com.seaofnodes.simple.type.Type;
-import com.seaofnodes.simple.type.Field;
-
-import java.util.BitSet;
-
-/**
- * Load represents extracting a value from inside a memory object,
- * in chapter 10 this means Struct fields.
- */
-public class LoadNode extends MemOpNode {
-
-    Type _declaredType;
-    /**
-     * Load a value from a ptr.field.
-     *
-     * @param name  The field we are loading
-     * @param memSlice The memory alias node - this is updated after a Store
-     * @param memPtr The ptr to the struct from where we load a field
-     */
-    public LoadNode(String name, int alias, Type glb, Node memSlice, Node memPtr) {
-        super(name, alias, memSlice, memPtr, null);
-        _declaredType = glb;
-    }
-
-    @Override
-    public String label() { return "Load"; }
-
-    @Override
-    StringBuilder _print1(StringBuilder sb, BitSet visited) { return sb.append(".").append(_name); }
-
-    @Override
-    public Type compute() {
-        return _declaredType;
-    }
-
-    @Override
-    public Node idealize() {
-
-        // Simple Load-after-Store on same address.
-        if( mem() instanceof StoreNode st &&
-            ptr() == st.ptr() ) { // Must check same object
-            assert Utils.eq(_name,st._name); // Equiv class aliasing is perfect
-            return st.val();
-        }
-
-        // Push a Load up through a Phi, as long as it collapses on at least
-        // one arm.  If at a Loop, the backedge MUST collapse - else we risk
-        // spinning the same transform around the loop indefinitely.
-        //   BEFORE (2 Sts, 1 Ld):          AFTER (1 St, 0 Ld):
-        //   if( pred ) ptr.x = e0;         val = pred ? e0
-        //   else       ptr.x = e1;                    : e1;
-        //   val = ptr.x;                   ptr.x = val;
-        if( mem() instanceof PhiNode memphi && memphi.region()._type == Type.CONTROL && memphi.nIns()== 3 ) {
-            // Profit on RHS/Loop backedge
-            if( profit(memphi,2) ||
-                // Else must not be a loop to count profit on LHS.
-                (!(memphi.region() instanceof LoopNode) && profit(memphi,1)) ) {
-                Node ld1 = new LoadNode(_name,_alias,_declaredType,memphi.in(1),ptr()).peephole();
-                Node ld2 = new LoadNode(_name,_alias,_declaredType,memphi.in(2),ptr()).peephole();
-                return new PhiNode(_name,_type,memphi.region(),ld1,ld2);
-            }
-        }
-
-        return null;
-    }
-
-    // Profitable if we find a matching Store on this Phi arm.
-    private boolean profit(PhiNode phi, int idx) {
-        Node px = phi.in(idx);
-        return px!=null && px.addDep(this) instanceof StoreNode st1 && ptr()==st1.ptr();
-    }
-}
diff --git a/chapter10/src/main/java/com/seaofnodes/simple/node/LoopNode.java b/chapter10/src/main/java/com/seaofnodes/simple/node/LoopNode.java
deleted file mode 100644
index a0ba973e..00000000
--- a/chapter10/src/main/java/com/seaofnodes/simple/node/LoopNode.java
+++ /dev/null
@@ -1,31 +0,0 @@
-package com.seaofnodes.simple.node;
-
-import com.seaofnodes.simple.type.Type;
-
-import java.util.BitSet;
-
-public class LoopNode extends RegionNode {
-
-    public LoopNode( Node entry ) { super(null,entry,null); }
-
-    Node entry() { return in(1); }
-    Node back () { return in(2); }
-
-    @Override
-    public String label() { return "Loop"; }
-
-    @Override
-    public Type compute() {
-        if( inProgress() ) return Type.CONTROL;
-        return entry()._type;
-    }
-
-    @Override
-    public Node idealize() {
-        return inProgress() ? null : super.idealize();
-    }
-
-    // Bypass Region idom, same as the default idom() using use entry in(1) instead of in(0)
-    @Override int idepth() { return _idepth!=0 ? _idepth : cacheIDepth(entry().idepth()+1); }
-    @Override Node idom() { return entry(); }
-}
diff --git a/chapter10/src/main/java/com/seaofnodes/simple/node/MemOpNode.java b/chapter10/src/main/java/com/seaofnodes/simple/node/MemOpNode.java
deleted file mode 100644
index 08e08bbf..00000000
--- a/chapter10/src/main/java/com/seaofnodes/simple/node/MemOpNode.java
+++ /dev/null
@@ -1,40 +0,0 @@
-package com.seaofnodes.simple.node;
-
-import com.seaofnodes.simple.type.Field;
-import com.seaofnodes.simple.type.Type;
-import com.seaofnodes.simple.type.TypeMemPtr;
-
-/**
- * Convenience common base for Load and Store.
- */
-public abstract class MemOpNode extends Node {
-
-    public final String _name;
-    public final int _alias;
-
-    public MemOpNode(String name, int alias, Node memSlice, Node memPtr, Node value) {
-        super(null, memSlice, memPtr, value);
-        _name  = name;
-        _alias = alias;
-    }
-
-    public Node mem() { return in(1); }
-    public Node ptr() { return in(2); }
-
-    @Override
-    boolean eq(Node n) {
-        MemOpNode mem = (MemOpNode)n; // Invariant
-        return _alias==mem._alias;    // When comparing types error to use "equals"; always use "=="
-    }
-
-    @Override
-    int hash() { return _alias; }
-
-    @Override
-    String err() {
-        Type ptr = ptr()._type;
-        return (ptr==Type.BOTTOM || (ptr instanceof TypeMemPtr tmp && tmp._nil) )
-            ? "Might be null accessing '" + _name + "'"
-            : null;
-    }
-}
diff --git a/chapter10/src/main/java/com/seaofnodes/simple/node/MinusNode.java b/chapter10/src/main/java/com/seaofnodes/simple/node/MinusNode.java
deleted file mode 100644
index 8b1b73bf..00000000
--- a/chapter10/src/main/java/com/seaofnodes/simple/node/MinusNode.java
+++ /dev/null
@@ -1,34 +0,0 @@
-package com.seaofnodes.simple.node;
-
-import com.seaofnodes.simple.type.Type;
-import com.seaofnodes.simple.type.TypeInteger;
-
-import java.util.BitSet;
-
-public class MinusNode extends Node {
-    public MinusNode(Node in) { super(null, in); }
-
-    @Override public String label() { return "Minus"; }
-
-    @Override
-    StringBuilder _print1(StringBuilder sb, BitSet visited) {
-        in(1)._print0(sb.append("(-"), visited);
-        return sb.append(")");
-    }
-
-    @Override
-    public Type compute() {
-        if (in(1)._type instanceof TypeInteger i0)
-            return i0.isConstant() ? TypeInteger.constant(-i0.value()) : i0;
-        return in(1)._type==Type.TOP ? TypeInteger.TOP : TypeInteger.BOT;
-    }
-
-    @Override
-    public Node idealize() {
-        // -(-x) is x
-        if( in(1) instanceof MinusNode minus )
-            return minus.in(1);
-
-        return null;
-    }
-}
diff --git a/chapter10/src/main/java/com/seaofnodes/simple/node/MulNode.java b/chapter10/src/main/java/com/seaofnodes/simple/node/MulNode.java
deleted file mode 100644
index 97721ce3..00000000
--- a/chapter10/src/main/java/com/seaofnodes/simple/node/MulNode.java
+++ /dev/null
@@ -1,59 +0,0 @@
-package com.seaofnodes.simple.node;
-
-import com.seaofnodes.simple.type.Type;
-import com.seaofnodes.simple.type.TypeInteger;
-
-import java.util.BitSet;
-
-public class MulNode extends Node {
-    public MulNode(Node lhs, Node rhs) { super(null, lhs, rhs); }
-
-    @Override public String label() { return "Mul"; }
-
-    @Override
-    StringBuilder _print1(StringBuilder sb, BitSet visited) {
-        in(1)._print0(sb.append("("), visited);
-        in(2)._print0(sb.append("*"), visited);
-        return sb.append(")");
-    }
-
-    @Override
-    public Type compute() {
-        Type t1 = in(1)._type, t2 = in(2)._type;
-        if( t1==Type.TOP || t1==TypeInteger.TOP ||
-            t2==Type.TOP || t2==TypeInteger.TOP )
-            return TypeInteger.TOP;
-        if (t1 instanceof TypeInteger i0 &&
-            t2 instanceof TypeInteger i1) {
-            if (i0.isConstant() && i1.isConstant())
-                return TypeInteger.constant(i0.value()*i1.value());
-        }
-        return TypeInteger.BOT;
-    }
-
-    @Override
-    public Node idealize() {
-        Node lhs = in(1);
-        Node rhs = in(2);
-        Type t1 = lhs._type;
-        Type t2 = rhs._type;
-
-        // Mul of 1.  We do not check for (1*x) because this will already
-        // canonicalize to (x*1)
-        if ( t2.isConstant() && t2 instanceof TypeInteger i && i.value()==1 )
-            return lhs;
-
-        // Move constants to RHS: con*arg becomes arg*con
-        if ( t1.isConstant() && !t2.isConstant() )
-            return swap12();
-
-        // Do we have ((x * (phi cons)) * con) ?
-        // Do we have ((x * (phi cons)) * (phi cons)) ?
-        // Push constant up through the phi: x * (phi con0*con0 con1*con1...)
-        Node phicon = AddNode.phiCon(this,true);
-        if( phicon!=null ) return phicon;
-
-        return null;
-    }
-    @Override Node copy(Node lhs, Node rhs) { return new MulNode(lhs,rhs); }
-}
diff --git a/chapter10/src/main/java/com/seaofnodes/simple/node/MultiNode.java b/chapter10/src/main/java/com/seaofnodes/simple/node/MultiNode.java
deleted file mode 100644
index 2743bd19..00000000
--- a/chapter10/src/main/java/com/seaofnodes/simple/node/MultiNode.java
+++ /dev/null
@@ -1,14 +0,0 @@
-package com.seaofnodes.simple.node;
-
-public abstract class MultiNode extends Node {
-
-    public MultiNode(Node... inputs) { super(inputs); }
-
-    // Find a projection by index
-    ProjNode proj( int idx ) {
-        for( Node out : _outputs )
-            if( out instanceof ProjNode prj && prj._idx==idx )
-                return prj;
-        return null;
-    }
-}
diff --git a/chapter10/src/main/java/com/seaofnodes/simple/node/NewNode.java b/chapter10/src/main/java/com/seaofnodes/simple/node/NewNode.java
deleted file mode 100644
index b13462f5..00000000
--- a/chapter10/src/main/java/com/seaofnodes/simple/node/NewNode.java
+++ /dev/null
@@ -1,37 +0,0 @@
-package com.seaofnodes.simple.node;
-
-import com.seaofnodes.simple.type.Type;
-import com.seaofnodes.simple.type.TypeMemPtr;
-
-import java.util.BitSet;
-
-public class NewNode extends Node {
-
-    TypeMemPtr _ptr;
-
-    public NewNode(TypeMemPtr ptr, Node ctrl) {
-        super(ctrl);
-        this._ptr = ptr;
-    }
-
-    @Override
-    public String label() { return "new"; }
-
-    @Override
-    StringBuilder _print1(StringBuilder sb, BitSet visited) {
-        sb.append("new ");
-        return sb.append(_ptr._obj.str());
-    }
-
-    @Override
-    public Type compute() { return _ptr; }
-
-    @Override
-    public Node idealize() { return null; }
-
-    @Override
-    boolean eq(Node n) { return this == n; }
-
-    @Override
-    int hash() { return _ptr.hashCode(); }
-}
diff --git a/chapter10/src/main/java/com/seaofnodes/simple/node/Node.java b/chapter10/src/main/java/com/seaofnodes/simple/node/Node.java
deleted file mode 100644
index eb6c1697..00000000
--- a/chapter10/src/main/java/com/seaofnodes/simple/node/Node.java
+++ /dev/null
@@ -1,633 +0,0 @@
-package com.seaofnodes.simple.node;
-
-import com.seaofnodes.simple.Parser;
-
-import com.seaofnodes.simple.IRPrinter;
-import com.seaofnodes.simple.IterPeeps;
-import com.seaofnodes.simple.Utils;
-import com.seaofnodes.simple.type.Type;
-
-import java.util.*;
-import java.util.function.Function;
-
-/**
- * All Nodes in the Sea of Nodes IR inherit from the Node class.
- * The Node class provides common functionality used by all subtypes.
- * Subtypes of Node specialize by overriding methods.
- */
-public abstract class Node {
-
-    /**
-     * Each node has a unique dense Node ID within a compilation context
-     * The ID is useful for debugging, for using as an offset in a bitvector,
-     * as well as for computing equality of nodes (to be implemented later).
-     */
-    public final int _nid;
-
-    /**
-     * Inputs to the node. These are use-def references to Nodes.
-     * <p>
-     * Generally fixed length, ordered, nulls allowed, no unused trailing space.
-     * Ordering is required because e.g. "a/b" is different from "b/a".
-     * The first input (offset 0) is often a {@link #isCFG} node.
-     */
-    public final ArrayList<Node> _inputs;
-
-    /**
-     * Outputs reference Nodes that are not null and have this Node as an
-     * input.  These nodes are users of this node, thus these are def-use
-     * references to Nodes.
-     * <p>
-     * Outputs directly match inputs, making a directed graph that can be
-     * walked in either direction.  These outputs are typically used for
-     * efficient optimizations but otherwise have no semantics meaning.
-     */
-    public final ArrayList<Node> _outputs;
-
-
-    /**
-     * Current computed type for this Node.  This value changes as the graph
-     * changes and more knowledge is gained about the program.
-     */
-    public Type _type;
-
-
-    /**
-     * A private Global Static mutable counter, for unique node id generation.
-     * To make the compiler multithreaded, this field will have to move into a TLS.
-     * Starting with value 1, to avoid bugs confusing node ID 0 with uninitialized values.
-     * */
-    private static int UNIQUE_ID = 1;
-    public static int UID() { return UNIQUE_ID; }
-
-    protected Node(Node... inputs) {
-        _nid = UNIQUE_ID++; // allocate unique dense ID
-        _inputs = new ArrayList<>();
-        Collections.addAll(_inputs,inputs);
-        _outputs = new ArrayList<>();
-        for( Node n : _inputs )
-            if( n != null )
-                n.addUse( this );
-    }
-
-    // Easy reading label for debugger, e.g. "Add" or "Region" or "EQ"
-    public abstract String label();
-
-    // Unique label for debugging, e.g. "Add12" or "Region30" or "EQ99"
-    public String uniqueName() {
-        return label() + _nid;
-    }
-
-    // ------------------------------------------------------------------------
-
-    // Debugger Printing.
-
-    // {@code toString} is what you get in the debugger.  It has to print 1
-    // line (because this is what a debugger typically displays by default) and
-    // has to be robust with broken graph/nodes.
-    @Override
-    public final String toString() {  return print(); }
-
-    // This is a *deep* print.  This version will fail on cycles, which we will
-    // correct later when we can parse programs with loops.  We print with a
-    // tik-tok style; the common _print0 calls the per-Node _print1, which
-    // calls back to _print0;
-    public final String print() {
-        return _print0(new StringBuilder(), new BitSet()).toString();
-    }
-
-    // This is the common print: check for repeats, check for DEAD and print
-    // "DEAD" else call the per-Node print1.
-    final StringBuilder _print0(StringBuilder sb, BitSet visited) {
-        if (visited.get(_nid) && !(this instanceof ConstantNode) )
-            return sb.append(label());
-        visited.set(_nid);
-        return isDead()
-            ? sb.append(uniqueName()).append(":DEAD")
-            : _print1(sb, visited);
-    }
-    // Every Node implements this; a partial-line recursive print
-    abstract StringBuilder _print1(StringBuilder sb, BitSet visited);
-
-    public String p(int depth) { return IRPrinter.prettyPrint(this,depth); }
-
-    public boolean isMultiHead() { return false; }
-    public boolean isMultiTail() { return false; }
-
-    // ------------------------------------------------------------------------
-    // Graph Node & Edge manipulation
-
-    /**
-     * Gets the ith input node
-     * @param i Offset of the input node
-     * @return Input node or null
-     */
-    public Node in(int i) { return _inputs.get(i); }
-    public Node out(int i) { return _outputs.get(i); }
-
-    public int nIns() { return _inputs.size(); }
-
-    public int nOuts() { return _outputs.size(); }
-
-    public boolean isUnused() { return nOuts() == 0; }
-
-    public boolean isCFG() { return false; }
-
-    public boolean isMem() { return false; }
-
-    /**
-     * Change a <em>def</em> into a Node.  Keeps the edges correct, by removing
-     * the corresponding <em>use->def</em> edge.  This may make the original
-     * <em>def</em> go dead.  This function is co-recursive with {@link #kill}.
-     * <p>
-
-     * This method is the normal path for altering a Node, because it does the
-     * proper default edge maintenance.  It also <em>immediately</em> kills
-     * Nodes that lose their last use; at times care must be taken to avoid
-     * killing Nodes that are being used without having an output Node.  This
-     * definitely happens in the middle of recursive {@link #peephole} calls.
-     *
-     * @param idx which def to set
-     * @param new_def the new definition
-     * @return new_def for flow coding
-     */
-    public Node setDef(int idx, Node new_def ) {
-        unlock();
-        Node old_def = in(idx);
-        if( old_def == new_def ) return new_def; // No change
-        // If new def is not null, add the corresponding def->use edge
-        // This needs to happen before removing the old node's def->use edge as
-        // the new_def might get killed if the old node kills it recursively.
-        if( new_def != null )
-            new_def.addUse(this);
-        if( old_def != null &&  // If the old def exists, remove a def->use edge
-            old_def.delUse(this) ) // If we removed the last use, the old def is now dead
-            old_def.kill();     // Kill old def
-        // Set the new_def over the old (killed) edge
-        _inputs.set(idx,new_def);
-        moveDepsToWorklist();
-        // Return self for easy flow-coding
-        return new_def;
-    }
-
-    // Remove the numbered input, compressing the inputs in-place.  This
-    // shuffles the order deterministically - which is suitable for Region and
-    // Phi, but not for every Node.  If the def goes dead, it is recursively
-    // killed, which may include 'this' Node.
-    Node delDef(int idx) {
-        unlock();
-        Node old_def = in(idx);
-        if( old_def != null &&  // If the old def exists, remove a def->use edge
-            old_def.delUse(this) ) // If we removed the last use, the old def is now dead
-            old_def.kill();     // Kill old def
-        old_def.moveDepsToWorklist();
-        Utils.del(_inputs, idx);
-        return this;
-    }
-
-    /**
-     * Add a new def to an existing Node.  Keep the edges correct by
-     * adding the corresponding <em>def->use</em> edge.
-     *
-     * @param new_def the new definition, appended to the end of existing definitions
-     * @return new_def for flow coding
-     */
-    Node addDef(Node new_def) {
-        unlock();
-        // Add use->def edge
-        _inputs.add(new_def);
-        // If new def is not null, add the corresponding def->use edge
-        if( new_def != null )
-            new_def.addUse(this);
-        return new_def;
-    }
-
-    // Breaks the edge invariants, used temporarily
-    protected <N extends Node> void addUse(N n) { _outputs.add(n); }
-
-    // Remove node 'use' from 'def's (i.e. our) output list, by compressing the list in-place.
-    // Return true if the output list is empty afterward.
-    // Error is 'use' does not exist; ok for 'use' to be null.
-    protected boolean delUse( Node use ) {
-        Utils.del(_outputs, Utils.find(_outputs, use));
-        return _outputs.isEmpty();
-    }
-
-    // Shortcut for "popping" n nodes.  A "pop" is basically a
-    // setDef(last,null) followed by lowering the nIns() count.
-    void popN(int n) {
-        unlock();
-        for( int i=0; i<n; i++ ) {
-            Node old_def = _inputs.removeLast();
-            if( old_def != null &&     // If it exists and
-                old_def.delUse(this) ) // If we removed the last use, the old def is now dead
-                old_def.kill();        // Kill old def
-        }
-    }
-
-    /**
-     * Kill a Node with no <em>uses</em>, by setting all of its <em>defs</em>
-     * to null.  This may recursively kill more Nodes, and is basically dead
-     * code elimination.
-     */
-    public void kill( ) {
-        unlock();
-        assert isUnused();      // Has no uses, so it is dead
-        _type=null;             // Flag as dead
-        while( nIns()>0 ) { // Set all inputs to null, recursively killing unused Nodes
-            Node old_def = _inputs.removeLast();
-            if( old_def != null ) {
-                IterPeeps.add(old_def);// Revisit neighbor because removed use
-                if( old_def.delUse(this) ) // If we removed the last use, the old def is now dead
-                    old_def.kill();        // Kill old def
-            }
-        }
-        assert isDead();        // Really dead now
-    }
-
-    // Mostly used for asserts and printing.
-    public boolean isDead() { return isUnused() && nIns()==0 && _type==null; }
-
-    // Shortcuts to stop DCE mid-parse
-    // Add bogus null use to keep node alive
-    public <N extends Node> N keep() { addUse(null); return (N)this; }
-    // Remove bogus null.
-    public <N extends Node> N unkeep() { delUse(null); return (N)this; }
-    // Test "keep" status
-    public boolean iskeep() { return Utils.find(_outputs,null) != -1; }
-
-
-    // Replace self with nnn in the graph, making 'this' go dead
-    public void subsume( Node nnn ) {
-        assert nnn!=this;
-        while( nOuts() > 0 ) {
-            Node n = _outputs.removeLast();
-            n.unlock();
-            int idx = Utils.find(n._inputs, this);
-            n._inputs.set(idx,nnn);
-            nnn.addUse(n);
-        }
-        kill();
-    }
-
-    // ------------------------------------------------------------------------
-    // Graph-based optimizations
-
-    /**
-     * Try to peephole at this node and return a better replacement Node.
-     * Always returns some not-null Node (often this).
-     */
-    public final Node peephole() {
-        var obs = IterPeeps.midAssert() ? null : Parser.PARSER == null ? null : Parser.PARSER._obs;
-        if( obs != null ) obs.before(this);
-        Node n = peepholeOpt();
-        Node rez = n == null ? this : deadCodeElim(n.peephole());
-        if( obs != null ) obs.after(this, n == null ? null : rez, false);
-        return rez;
-    }
-
-    /**
-     * Try to peephole at this node and return a better replacement Node if
-     * possible.  We compute a {@link Type} and then check and replace:
-     * <ul>
-     * <li>if the Type {@link Type#isConstant}, we replace with a {@link ConstantNode}</li>
-     * <li>in a future chapter we will look for a
-     * <a href="https://en.wikipedia.org/wiki/Common_subexpression_elimination">Common Subexpression</a>
-     * to eliminate.</li>
-     * <li>we ask the Node for a better replacement.  The "better replacement"
-     * is things like {@code (1+2)} becomes {@code 3} and {@code (1+(x+2))} becomes
-     * {@code (x+(1+2))}.  By canonicalizing expressions we fold common addressing
-     * math constants, remove algebraic identities and generally simplify the
-     * code. </li>
-     *
-     * Unlike peephole above, this explicitly returns null for no-change, or not-null
-     * for a better replacement (which can be this).
-     * </ul>
-     */
-    public final Node peepholeOpt( ) {
-        ITER_CNT++;
-        // Compute initial or improved Type
-        Type old = setType(compute());
-
-        // Replace constant computations from non-constants with a constant node
-        if( !(this instanceof ConstantNode) && _type.isHighOrConst() )
-            return new ConstantNode(_type).peepholeOpt();
-
-        // Global Value Numbering
-        if( _hash==0 ) {
-            Node n = GVN.get(this); // Will set _hash as a side effect
-            if( n==null )
-                GVN.put(this,this);  // Put in table now
-            else {
-                // Because of random worklist ordering, the two equal nodes
-                // might have different types.  Because of monotonicity, both
-                // types are valid.  To preserve monotonicity, the resulting
-                // shared Node has to have the best of both types.
-                n.setType(n._type.join(_type));
-                _hash = 0; // Clear, since it never went in the table
-                return deadCodeElim(n);// Return previous; does Common Subexpression Elimination
-            }
-        }
-
-        // Ask each node for a better replacement
-        Node n = idealize();
-        if( n != null )         // Something changed
-            return n;           // Report progress
-
-        if( old==_type ) ITER_NOP_CNT++;
-        return old==_type ? null : this; // Report progress
-    }
-    public static int ITER_CNT, ITER_NOP_CNT;
-
-    // m is the new Node, self is the old.
-    // Return 'm', which may have zero uses but is alive nonetheless.
-    // If self has zero uses (and is not 'm'), {@link #kill} self.
-    private Node deadCodeElim(Node m) {
-        // If self is going dead and not being returned here (Nodes returned
-        // from peephole commonly have no uses (yet)), then kill self.
-        if( m != this && isUnused() && !isDead() ) {
-            // Killing self - and since self recursively kills self's inputs we
-            // might end up killing 'm', which we are returning as a live Node.
-            // So we add a bogus extra null output edge to stop kill().
-            m.keep();      // Keep m alive
-            kill();        // Kill self because replacing with 'm'
-            m.unkeep();    // Okay to peephole m
-        }
-        return m;
-    }
-
-    /**
-     * This function needs to be
-     * <a href="https://en.wikipedia.org/wiki/Monotonic_function">Monotonic</a>
-     * as it is part of a Monotone Analysis Framework.
-     * <a href="https://www.cse.psu.edu/~gxt29/teaching/cse597s21/slides/08monotoneFramework.pdf">See for example this set of slides</a>.
-     * <p>
-     * For Chapter 2, all our Types are really integer constants, and so all
-     * the needed properties are trivially true, and we can ignore the high
-     * theory.  Much later on, this will become important and allow us to do
-     * many fancy complex optimizations trivially... because theory.
-     * <p>
-     * {@link #compute()} needs to be stand-alone, and cannot recursively call compute
-     * on its inputs, because programs are cyclic (have loops!) and this will just
-     * infinitely recurse until stack overflow.  Instead, compute typically
-     * computes a new type from the {@link #_type} field of its inputs.
-     */
-    public abstract Type compute();
-
-    // Set the type.  Assert monotonic progress.
-    // If changing, add users to worklist.
-    public Type setType(Type type) {
-        Type old = _type;
-        assert old==null || type.isa(old); // Since _type not set, can just re-run this in assert in the debugger
-        if( old == type ) return old;
-        _type = type;       // Set _type late for easier assert debugging
-        IterPeeps.addAll(_outputs);
-        moveDepsToWorklist();
-        return old;
-    }
-
-
-    /**
-     * This function rewrites the current Node into a more "idealized" form.
-     * This is the bulk of our peephole rewrite rules, and we use this to
-     * e.g. turn arbitrary collections of adds and multiplies with mixed
-     * constants into a normal form that's easy for hardware to implement.
-     * Example: An array addressing expression:
-     * <pre>   ary[idx+1]</pre>
-     * might turn into Sea-of-Nodes IR:
-     * <pre>   (ary+12)+((idx+1) * 4)</pre>
-     * This expression can then be idealized into:
-     * <pre>   ary + ((idx*4) + (12 + (1*4)))</pre>
-     * And more folding:
-     * <pre>   ary + ((idx<<2) + 16)</pre>
-     * And during code-gen:
-     * <pre>   MOV4 Rary,Ridx,16 // or some such hardware-specific notation </pre>
-     * <p>
-     * {@link #idealize} has a very specific calling convention:
-     * <ul>
-     * <li>If NO change is made, return {@code null}
-     * <li>If ANY change is made, return not-null; this can be {@code this}
-     * <li>The returned Node does NOT call {@link #peephole} on itself; the {@link #peephole} call will recursively peephole it.
-     * <li>Any NEW nodes that are not directly returned DO call {@link #peephole}.
-     * </ul>
-     * <p>
-     * Examples:
-     * <table border="3">
-     * <tr><th>    before       </th><th>       after     </th><th>return </th><th>comment  </th></tr>
-     * <tr><td>{@code (x+5)    }</td><td>{@code   (x+5)  }</td><td>{@code null  }</td><td>No change</td></tr>
-     * <tr><td>{@code (5+x)    }</td><td>{@code   (x+5)  }</td><td>{@code this  }</td><td>Swapped arguments</td></tr>
-     * <tr><td>{@code ((x+1)+2)}</td><td>{@code (x+(1+2))}</td><td>{@code (x+_) }</td><td>Returns 2 new Nodes</td></tr>
-     * </table>
-     *
-     * The last entry deserves more discussion.  The new Node {@code (1+2)}
-     * created in {@link #idealize} calls {@link #peephole} (which then folds
-     * into a constant).  The other new Node {@code (x+3)} does not call
-     * peephole, because it is returned and peephole itself will recursively
-     * call peephole.
-     * <p>
-     * Since idealize calls peephole and peephole calls idealize, you must be
-     * careful that all idealizations are <em>monotonic</em>: all transforms
-     * remove some feature, so that the set of available transforms always
-     * shrinks.  If you don't, you risk an infinite peephole loop!
-     *
-     * @return Either a new or changed node, or null for no changes.
-     */
-    public abstract Node idealize();
-
-
-    // Some of the peephole rules get complex, and search further afield than
-    // just the nearest neighbor.  These peepholes can fail the pattern match
-    // on a node some distance away, and if that node ever changes we should
-    // retry the peephole.  Track a set of Nodes dependent on `this`, and
-    // revisit them if `this` changes.
-    ArrayList<Node> _deps;
-    public int nDeps() { return _deps == null ? 0 : _deps.size(); }
-    public Node dep(int idx) { return _deps.get(idx); }
-
-    /**
-     * Add a node to the list of dependencies.  Only add it if its not an input
-     * or output of this node, that is, it is at least one step away.  The node
-     * being added must benefit from this node being peepholed.
-     */
-    Node addDep( Node dep ) {
-        // Running peepholes during the big assert cannot have side effects
-        // like adding dependencies.
-        if( IterPeeps.midAssert() ) return this;
-        var obs = IterPeeps.midAssert() ? null : Parser.PARSER == null ? null : Parser.PARSER._obs;
-        if( obs != null ) obs.dep(this, dep);
-        if( _deps==null ) _deps = new ArrayList<>();
-        if( Utils.find(_deps  ,dep) != -1 ) return this; // Already on list
-        if( Utils.find(_inputs,dep) != -1 ) return this; // No need for deps on immediate neighbors
-        if( Utils.find(_outputs,dep)!= -1 ) return this;
-        _deps.add(dep);
-        return this;
-    }
-
-    // Move the dependents onto a worklist, and clear for future dependents.
-    public void moveDepsToWorklist( ) {
-        if( _deps==null ) return;
-        IterPeeps.addAll(_deps);
-        _deps.clear();
-    }
-
-
-    // Global Value Numbering.  Hash over opcode and inputs; hits in this table
-    // are structurally equal.
-    public static final HashMap<Node,Node> GVN = new HashMap<>();
-
-    // Two nodes are equal if they have the same inputs and the same "opcode"
-    // which means the same Java class, plus same internal parts.
-    @Override public final boolean equals( Object o ) {
-        if( o==this ) return true;
-        if( o.getClass() != getClass() ) return false;
-        Node n = (Node)o;
-        int len = _inputs.size();
-        if( len != n._inputs.size() ) return false;
-        for( int i=0; i<len; i++ )
-            if( in(i) != n.in(i) )
-                return false;
-        return eq(n);
-    }
-    // Subclasses add extra checks (such as ConstantNodes have same constant),
-    // and can assume "this!=n" and has the same Java class.
-    boolean eq( Node n ) { return true; }
-
-
-    // Cached hash.  If zero, then not computed AND this Node is NOT in the GVN
-    // table - and can have its edges hacked (which will change his hash
-    // anyway).  If Non-Zero then this Node is IN the GVN table, or is being
-    // probed to see if it can be inserted.  His edges are "locked", because
-    // hacking his edges will change his hash.
-    int _hash;
-
-    // If the _hash is set, then the Node is in the GVN table; remove it.
-    void unlock() {
-        if( _hash==0 ) return;
-        Node old = GVN.remove(this); // Pull from table
-        assert old==this;
-        _hash=0;                // Out of table now
-    }
-
-
-    // Hash of opcode and inputs
-    @Override public final int hashCode() {
-        if( _hash != 0 ) return _hash;
-        int hash = hash();
-        for( Node n : _inputs )
-            if( n != null )
-                hash = hash ^ (hash<<17) ^ (hash>>13) ^ n._nid;
-        if( hash==0 ) hash = 0xDEADBEEF; // Bad hash, so use some junky thing
-        return (_hash=hash);
-    }
-    // Subclasses add extra hash info (such as ConstantNodes constant)
-    int hash() { return 0; }
-
-
-    // ------------------------------------------------------------------------
-    // Peephole utilities
-
-    // Swap inputs without letting either input go dead during the swap.
-    Node swap12() {
-        unlock();               // Hash is order dependent
-        Node tmp = in(1);
-        _inputs.set(1,in(2));
-        _inputs.set(2,tmp);
-        return this;
-    }
-
-    /**
-     * Does this node contain all constants?  Ignores in(0), as is usually
-     * control.  In an input is not a constant, we add dep as a dependency to
-     * it because dep can make progress if the input becomes a constant later.
-     * It is sufficient for one of the non-const inputs to have the dependency,
-     * so we don't bother checking the rest.
-     */
-    boolean allCons(Node dep) {
-        for( int i=1; i<nIns(); i++ )
-            if( !(in(i)._type.isConstant()) ) {
-                in(i).addDep(dep); // If in(i) becomes a constant later, will trigger some peephole
-                return false;
-            }
-        return true;
-    }
-
-
-    /**
-     * Immediate dominator tree depth, used to approximate a real IDOM depth
-     * during parsing where we do not have the whole program, and also
-     * peepholes change the CFG incrementally.
-     * <p>
-     * See {@link <a href="https://en.wikipedia.org/wiki/Dominator_(graph_theory)">...</a>}
-     */
-    public char _idepth;         // IDOM depth approx; Zero is unset; non-zero is cached legit
-
-    // Find the lowest common ancestor in the current dominator tree.
-    Node domLCA(Node rhs) {
-        if( rhs==null ) return this;
-        Node lhs = this;
-        while( lhs != rhs ) {
-            if( lhs==null || rhs==null ) return null;
-            int comp = lhs.idepth() - rhs.idepth();
-            if( comp >= 0 ) lhs = lhs.idom();
-            if( comp <= 0 ) rhs = rhs.idom();
-        }
-        return lhs;
-    }
-
-    int idepth() { return _idepth!=0 ? _idepth : cacheIDepth(idom().idepth()+1); }
-    // Zero depth means uncached. Check before narrowing so overflow cannot wrap.
-    final int cacheIDepth(int depth) {
-        assert 0 <= depth && depth <= Character.MAX_VALUE : "Dominator depth exceeds 65535";
-        return _idepth = (char)depth;
-    }
-
-
-    // Return the immediate dominator of this Node.
-    Node idom() { return in(0); }
-
-    // Make a shallow copy (same class) of this Node, with given inputs and
-    // empty outputs and a new Node ID.  The original inputs are ignored.
-    // Does not need to be implemented in isCFG() nodes.
-    Node copy(Node lhs, Node rhs) { throw Utils.TODO("Binary ops need to implement copy"); }
-
-    // Report any post-optimize errors
-    String err() { return null; }
-
-    /**
-     * Used to allow repeating tests in the same JVM.  This just resets the
-     * Node unique id generator, and is done as part of making a new Parser.
-     */
-    public static void reset() {
-        UNIQUE_ID = 1;
-        GVN.clear();
-        ITER_CNT = ITER_NOP_CNT = 0;
-    }
-
-
-    // Utility to walk the entire graph applying a function; return the first
-    // not-null result.
-    private static final BitSet WVISIT = new BitSet();
-    final public <E> E walk( Function<Node,E> pred ) {
-        assert WVISIT.isEmpty();
-        E rez = _walk(pred);
-        WVISIT.clear();
-        return rez;
-    }
-
-    private <E> E _walk( Function<Node,E> pred ) {
-        if( WVISIT.get(_nid) ) return null; // Been there, done that
-        WVISIT.set(_nid);
-        E x = pred.apply(this);
-        if( x != null ) return x;
-        for( Node def : _inputs  )  if( def != null && (x = def._walk(pred)) != null ) return x;
-        for( Node use : _outputs )  if( use != null && (x = use._walk(pred)) != null ) return x;
-        return null;
-    }
-
-    /**
-     * Debugging utility to find a Node by index
-     */
-    public Node find(int nid) {
-        return walk( n -> n._nid==nid ? n : null );
-    }
-}
diff --git a/chapter10/src/main/java/com/seaofnodes/simple/node/NotNode.java b/chapter10/src/main/java/com/seaofnodes/simple/node/NotNode.java
deleted file mode 100644
index 83141836..00000000
--- a/chapter10/src/main/java/com/seaofnodes/simple/node/NotNode.java
+++ /dev/null
@@ -1,42 +0,0 @@
-package com.seaofnodes.simple.node;
-
-import com.seaofnodes.simple.Utils;
-import com.seaofnodes.simple.type.*;
-import java.util.BitSet;
-
-public class NotNode extends Node {
-    public NotNode(Node in) { super(null, in); }
-
-    @Override public String label() { return "Not"; }
-
-    @Override
-    StringBuilder _print1(StringBuilder sb, BitSet visited) {
-        in(1)._print0(sb.append("(!"), visited);
-        return sb.append(")");
-    }
-
-    @Override
-    public Type compute() {
-        Type t0 = in(1)._type;
-        switch( t0 ) {
-        case TypeInteger i0:
-            return i0.isConstant() ? TypeInteger.constant(i0.value()==0 ? 1 : 0) : i0;
-        case TypeMemPtr p0:
-            // top->top, bot->bot, null->1, *void->0, not-null ptr->0, ptr/nil->bot
-            // If input in null then true
-            // If input is not null ptr then false
-            if( p0 == TypeMemPtr.TOP  )    return TypeInteger.TOP;
-            if( p0 == TypeMemPtr.NULLPTR ) return TypeInteger.constant(1);
-            if( !p0._nil )                 return TypeInteger.constant(0);
-            return TypeInteger.BOT;
-        case Type t:
-            if( t0.getClass() != Type.class )
-                // Only doing NOT on ints and ptrs
-                throw Utils.TODO();
-            return t0==Type.TOP ? TypeInteger.TOP : TypeInteger.BOT;
-        }
-    }
-
-    @Override
-    public Node idealize() { return null; }
-}
diff --git a/chapter10/src/main/java/com/seaofnodes/simple/node/PhiNode.java b/chapter10/src/main/java/com/seaofnodes/simple/node/PhiNode.java
deleted file mode 100644
index bdf50847..00000000
--- a/chapter10/src/main/java/com/seaofnodes/simple/node/PhiNode.java
+++ /dev/null
@@ -1,157 +0,0 @@
-package com.seaofnodes.simple.node;
-
-import com.seaofnodes.simple.type.Type;
-import com.seaofnodes.simple.type.TypeMem;
-import com.seaofnodes.simple.Utils;
-
-import java.util.BitSet;
-
-public class PhiNode extends Node {
-
-    final String _label;
-
-    // The Phi type we compute must stay within the domain of the Phi.
-    // Example Int stays Int, Ptr stays Ptr, Control stays Control, Mem stays Mem.
-    final Type _declaredType;
-
-    public PhiNode(String label, Type declaredType, Node... inputs) { super(inputs); _label = label;  assert declaredType!=null; _declaredType = declaredType; }
-
-    @Override public String label() { return "Phi_"+_label; }
-
-    @Override
-    StringBuilder _print1(StringBuilder sb, BitSet visited) {
-        if( !(region() instanceof RegionNode r) || r.inProgress() )
-            sb.append("Z");
-        sb.append("Phi(");
-        for( Node in : _inputs ) {
-            if (in == null) sb.append("____");
-            else in._print0(sb, visited);
-            sb.append(",");
-        }
-        sb.setLength(sb.length()-1);
-        sb.append(")");
-        return sb;
-    }
-
-    Node region() { return in(0); }
-    @Override public boolean isMultiTail() { return true; }
-    @Override
-    public boolean isMem() { return _declaredType instanceof TypeMem; }
-
-    @Override
-    public Type compute() {
-        if( !(region() instanceof RegionNode r) )
-            return region()._type==Type.XCONTROL ? Type.TOP : _type;
-        // During parsing Phis have to be computed type pessimistically.
-        if( r.inProgress() ) return _declaredType;
-        // Set type to local top of the starting type
-        Type t = _declaredType.glb().dual();
-        for (int i = 1; i < nIns(); i++)
-            // If the region's control input is live, add this as a dependency
-            // to the control because we can be peeped should it become dead.
-            if( r.in(i).addDep(this)._type != Type.XCONTROL )
-                t = t.meet(in(i)._type);
-        return t;
-    }
-
-    @Override
-    public Node idealize() {
-        if( !(region() instanceof RegionNode r ) )
-            return in(1);       // Input has collapse to e.g. starting control.
-        if( r.inProgress() || r.nIns()<=1 )
-            return null;        // Input is in-progress
-
-        // If we have only a single unique input, become it.
-        Node live = singleUniqueInput();
-        if (live != null)
-            return live;
-
-        // Pull "down" a common data op.  One less op in the world.  One more
-        // Phi, but Phis do not make code.
-        //   Phi(op(A,B),op(Q,R),op(X,Y)) becomes
-        //     op(Phi(A,Q,X), Phi(B,R,Y)).
-        Node op = in(1);
-        if( op.nIns()==3 && op.in(0)==null && !op.isCFG() && same_op() ) {
-            Node[] lhss = new Node[nIns()];
-            Node[] rhss = new Node[nIns()];
-            lhss[0] = rhss[0] = in(0); // Set Region
-            for( int i=1; i<nIns(); i++ ) {
-                lhss[i] = in(i).in(1);
-                rhss[i] = in(i).in(2);
-            }
-            Node phi_lhs = new PhiNode(_label, _declaredType,lhss).peephole();
-            Node phi_rhs = new PhiNode(_label, _declaredType,rhss).peephole();
-            return op.copy(phi_lhs,phi_rhs);
-        }
-
-        // If merging Phi(N, cast(N)) - we are losing the cast JOIN effects, so just remove.
-        if( nIns()==3 ) {
-            if( in(1) instanceof CastNode cast && cast.in(1).addDep(this)==in(2) ) return in(2);
-            if( in(2) instanceof CastNode cast && cast.in(1).addDep(this)==in(1) ) return in(1);
-        }
-        // If merging a null-checked null and the checked value, just use the value.
-        // if( val ) ..; phi(Region,False=0/null,True=val);
-        // then replace with plain val.
-        if( nIns()==3 ) {
-            int nullx = -1;
-            if( in(1)._type == in(1)._type.makeInit() ) nullx = 1;
-            if( in(2)._type == in(2)._type.makeInit() ) nullx = 2;
-            if( nullx != -1 ) {
-                Node val = in(3-nullx);
-                if( region().idom() instanceof IfNode iff && iff.pred().addDep(this)==val ) {
-                    // Must walk the idom on the null side to make sure we hit False.
-                    Node idom = region().in(nullx);
-                    while( idom.in(0) != iff ) idom = idom.idom();
-                    if( idom instanceof ProjNode proj && proj._idx==1 )
-                        return val;
-                }
-            }
-        }
-
-        return null;
-    }
-
-    private boolean same_op() {
-        for( int i=2; i<nIns(); i++ )
-            if( in(1).getClass() != in(i).getClass() )
-                return false;
-        return true;
-    }
-
-    /**
-     * If only single unique input, return it
-     */
-    private Node singleUniqueInput() {
-        if( region() instanceof LoopNode loop && loop.entry()._type == Type.XCONTROL )
-            return null;    // Dead entry loops just ignore and let the loop collapse
-        Node live = null;
-        for( int i=1; i<nIns(); i++ ) {
-            // If the region's control input is live, add this as a dependency
-            // to the control because we can be peeped should it become dead.
-            if( region().in(i).addDep(this)._type != Type.XCONTROL && in(i) != this )
-                if( live == null || live == in(i) ) live = in(i);
-                else return null;
-        }
-        return live;
-    }
-
-    @Override
-    boolean allCons(Node dep) {
-        if( !(region() instanceof RegionNode r) ) return false;
-        // When the region completes (is no longer in progress) the Phi can
-        // become a "all constants" Phi, and the "dep" might make progress.
-        addDep(dep);
-        if( r.inProgress() ) return false;
-        return super.allCons(dep);
-    }
-
-    // True if last input is null
-    public final boolean inProgress() {
-        return in(nIns()-1) == null;
-    }
-
-    // Never equal if inProgress
-    @Override boolean eq( Node n ) {
-        return !inProgress();
-    }
-}
diff --git a/chapter10/src/main/java/com/seaofnodes/simple/node/ProjNode.java b/chapter10/src/main/java/com/seaofnodes/simple/node/ProjNode.java
deleted file mode 100644
index 735fcdf3..00000000
--- a/chapter10/src/main/java/com/seaofnodes/simple/node/ProjNode.java
+++ /dev/null
@@ -1,59 +0,0 @@
-package com.seaofnodes.simple.node;
-
-import com.seaofnodes.simple.type.Type;
-import com.seaofnodes.simple.type.TypeMem;
-import com.seaofnodes.simple.type.TypeTuple;
-
-import java.util.BitSet;
-
-public class ProjNode extends Node {
-
-    // Which slice of the incoming multipart value
-    public final int _idx;
-
-    // Debugging label
-    public final String _label;
-
-    public ProjNode(MultiNode ctrl, int idx, String label) {
-        super(ctrl);
-        _idx = idx;
-        _label = label;
-    }
-
-    @Override
-    public String label() { return _label; }
-
-    @Override
-    StringBuilder _print1(StringBuilder sb, BitSet visited) { return sb.append(_label); }
-
-    @Override public boolean isCFG() { return _idx==0 || ctrl() instanceof IfNode; }
-    @Override public boolean isMultiTail() { return in(0).isMultiHead(); }
-    @Override public boolean isMem() { return _type instanceof TypeMem; }
-
-    public MultiNode ctrl() { return (MultiNode)in(0); }
-
-    @Override
-    public Type compute() {
-        Type t = in(0)._type;
-        return t instanceof TypeTuple tt ? tt._types[_idx] : Type.BOTTOM;
-    }
-
-    @Override
-    public Node idealize() {
-        if ( ctrl() instanceof IfNode iff ) {
-            if ( iff._type instanceof TypeTuple tt && tt._types[1 - _idx] == Type.XCONTROL )
-                return iff.in(0); // We become our input control
-
-            // Flip a negating if-test, to remove the not
-            if( iff.pred().addDep(this) instanceof NotNode not )
-                return new ProjNode((MultiNode)new IfNode(iff.ctrl(),not.in(1)).peephole(),1-_idx,_idx==0 ? "False" : "True");
-        }
-        return null;
-    }
-
-    @Override
-    boolean eq( Node n ) { return _idx == ((ProjNode)n)._idx; }
-
-    @Override
-    int hash() { return _idx; }
-}
diff --git a/chapter10/src/main/java/com/seaofnodes/simple/node/RegionNode.java b/chapter10/src/main/java/com/seaofnodes/simple/node/RegionNode.java
deleted file mode 100644
index f7a56503..00000000
--- a/chapter10/src/main/java/com/seaofnodes/simple/node/RegionNode.java
+++ /dev/null
@@ -1,118 +0,0 @@
-package com.seaofnodes.simple.node;
-
-import com.seaofnodes.simple.IterPeeps;
-import com.seaofnodes.simple.Utils;
-import com.seaofnodes.simple.type.Type;
-
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.BitSet;
-
-public class RegionNode extends Node {
-
-    public RegionNode(Node... nodes) { super(nodes); }
-
-    @Override
-    public String label() { return "Region"; }
-
-    @Override
-    StringBuilder _print1(StringBuilder sb, BitSet visited) {
-        return sb.append(label()).append(_nid);
-    }
-
-    @Override public boolean isCFG() { return true; }
-    @Override public boolean isMultiHead() { return true; }
-
-    @Override
-    public Type compute() {
-        if( inProgress() ) return Type.CONTROL;
-        Type t = Type.XCONTROL;
-        for (int i = 1; i < nIns(); i++)
-            t = t.meet(in(i)._type);
-        return t;
-    }
-
-    @Override
-    public Node idealize() {
-        if( inProgress() ) return null;
-        // Delete dead paths into a Region
-        int path = findDeadInput();
-        if( path != 0 &&
-            // Do not delete the entry path of a loop (ok to remove the back
-            // edge and make the loop a single-entry Region which folds away
-            // the Loop).  Folding the entry path confused the loop structure,
-            // moving the backedge to the entry point.
-            !(this instanceof LoopNode loop && loop.entry()==in(path)) ) {
-            // Cannot use the obvious output iterator here, because a Phi
-            // deleting an input might recursively delete *itself*.  This
-            // shuffles the output array, and we might miss iterating an
-            // unrelated Phi. So on rare occasions we repeat the loop to get
-            // all the Phis.
-            int nouts = 0;
-            while( nouts != nOuts() ) {
-                nouts = nOuts();
-                for( int i=0; i<nOuts(); i++ )
-                    if( out(i) instanceof PhiNode phi && phi.nIns()==nIns() ) {
-                        phi.delDef(path);
-                        IterPeeps.addAll(phi._outputs);
-                    }
-            }
-            return isDead() ? new ConstantNode(Type.XCONTROL) : delDef(path);
-        }
-        // If down to a single input, become that input
-        if( nIns()==2 && !hasPhi() )
-            return in(1);       // Collapse if no Phis; 1-input Phis will collapse on their own
-
-        // If a CFG diamond with no merging, delete: "if( pred ) {} else {};"
-        if( !hasPhi() &&       // No Phi users, just a control user
-            in(1) instanceof ProjNode p1 &&
-            in(2) instanceof ProjNode p2 &&
-            p1.in(0)==p2.in(0) &&
-            p1.in(0) instanceof IfNode iff )
-            return iff.ctrl();
-
-        return null;
-    }
-
-    private int findDeadInput() {
-        for( int i=1; i<nIns(); i++ )
-            if( in(i)._type==Type.XCONTROL )
-                return i;
-        return 0;               // All inputs alive
-    }
-
-    private boolean hasPhi() {
-        for( Node phi : _outputs )
-            if( phi instanceof PhiNode )
-                return true;
-        return false;
-    }
-
-    // Immediate dominator of Region is a little more complicated.
-    @Override int idepth() {
-        if( _idepth!=0 ) return _idepth;
-        int depth=0;
-        for( Node n : _inputs )
-            if( n!=null )
-                depth = Math.max(depth,n.idepth()+1);
-        return cacheIDepth(depth);
-    }
-
-    @Override Node idom() {
-        Node lca = null;
-        // Recompute from predecessors: CFG edits can change the dominator.
-        for( int i=1; i<nIns(); i++ )
-            lca = in(i).domLCA(lca);
-        return lca;
-    }
-
-    // True if last input is null
-    public final boolean inProgress() {
-        return nIns()>1 && in(nIns()-1) == null;
-    }
-
-    // Never equal if inProgress
-    @Override boolean eq( Node n ) {
-        return !inProgress();
-    }
-}
diff --git a/chapter10/src/main/java/com/seaofnodes/simple/node/ReturnNode.java b/chapter10/src/main/java/com/seaofnodes/simple/node/ReturnNode.java
deleted file mode 100644
index 92bda5bf..00000000
--- a/chapter10/src/main/java/com/seaofnodes/simple/node/ReturnNode.java
+++ /dev/null
@@ -1,55 +0,0 @@
-package com.seaofnodes.simple.node;
-
-import com.seaofnodes.simple.type.*;
-
-import java.util.BitSet;
-
-/**
- * The Return node has two inputs.  The first input is a control node and the
- * second is the data node that supplies the return value.
- * <p>
- * In this presentation, Return functions as a Stop node, since multiple <code>return</code> statements are not possible.
- * The Stop node will be introduced in Chapter 6 when we implement <code>if</code> statements.
- * <p>
- * The Return's output is the value from the data node.
- */
-public class ReturnNode extends Node {
-
-    public ReturnNode(Node ctrl, Node data, ScopeNode scope) {
-        super(ctrl, data);
-        // We lookup memory slices by the naming convention that they start with $
-        // We could also use implicit knowledge that all memory projects are at offset >= 2
-        String[] names = scope.reverseNames();
-        for (String name: names) {
-            if (!name.equals("$ctrl") && name.startsWith("$"))
-                addDef(scope.lookup(name));
-        }
-    }
-
-    public Node ctrl() { return in(0); }
-    public Node expr() { return in(1); }
-
-    @Override
-    public String label() { return "Return"; }
-
-    @Override
-    StringBuilder _print1(StringBuilder sb, BitSet visited) {
-        sb.append("return ");
-        expr()._print0(sb, visited);
-        return sb.append(";");
-    }
-
-    @Override public boolean isCFG() { return true; }
-
-    @Override
-    public Type compute() {
-        return TypeTuple.make(ctrl()._type,expr()._type);
-    }
-
-    @Override
-    public Node idealize() {
-        if( ctrl()._type==Type.XCONTROL )
-            return ctrl();
-        return null;
-    }
-}
diff --git a/chapter10/src/main/java/com/seaofnodes/simple/node/ScopeNode.java b/chapter10/src/main/java/com/seaofnodes/simple/node/ScopeNode.java
deleted file mode 100644
index 455f4b3a..00000000
--- a/chapter10/src/main/java/com/seaofnodes/simple/node/ScopeNode.java
+++ /dev/null
@@ -1,304 +0,0 @@
-package com.seaofnodes.simple.node;
-
-import com.seaofnodes.simple.IterPeeps;
-import com.seaofnodes.simple.type.Type;
-import com.seaofnodes.simple.Utils;
-import com.seaofnodes.simple.type.TypeMemPtr;
-
-import java.util.*;
-
-/**
- * The Scope node is purely a parser helper - it tracks names to nodes with a
- * stack of scopes.
- */
-public class ScopeNode extends Node {
-
-    /**
-     * The control is a name that binds to the currently active control
-     * node in the graph
-     */
-    public static final String CTRL = "$ctrl";
-    public static final String ARG0 = "arg";
-
-    /**
-     * Names for every input edge
-     */
-    public final Stack<HashMap<String, Integer>> _scopes;
-
-    /**
-     * Tracks declared types for every name
-     */
-    public Stack<HashMap<String, Type>> _types;
-
-
-    // A new ScopeNode
-    public ScopeNode() {
-        _scopes = new Stack<>();
-        _types  = new Stack<>();
-        _type = Type.BOTTOM;
-    }
-
-
-    @Override public String label() { return "Scope"; }
-
-    @Override
-    StringBuilder _print1(StringBuilder sb, BitSet visited) {
-        sb.append("Scope[ ");
-        String[] names = reverseNames();
-        for( int j=0; j<nIns(); j++ ) {
-            sb.append(names[j]).append(":");
-            Node n = in(j);
-            while( n instanceof ScopeNode loop ) {
-                sb.append("Lazy_");
-                n = loop.in(j);
-            }
-            n._print0(sb, visited).append(" ");
-        }
-        sb.setLength(sb.length()-1);
-        return sb.append("]");
-    }
-
-    /**
-     * Recover the names for all variable bindings.
-     * The result is an array of names that is aligned with the
-     * inputs to the Node.
-     *
-     * This is an expensive operation.
-     */
-    public String[] reverseNames() {
-        String[] names = new String[nIns()];
-        for( HashMap<String,Integer> syms : _scopes )
-            for( String name : syms.keySet() )
-                names[syms.get(name)] = name;
-        return names;
-    }
-
-    @Override public Type compute() { return Type.BOTTOM; }
-
-    @Override public Node idealize() { return null; }
-
-    public void push() { _scopes.push(new HashMap<>());  _types.push(new HashMap<>()); }
-    public void pop() { popN(_scopes.pop().size()); _types.pop(); }
-
-    /**
-     * Create a new name in the current scope
-     */
-    public Node define( String name, Type declaredType, Node n ) {
-        HashMap<String,Integer> syms = _scopes.lastElement();
-        _types.lastElement().put(name,declaredType);
-        if( syms.put(name,nIns()) != null )
-            return null;        // Double define
-        return addDef(n);
-    }
-    /**
-     * Lookup a name in all scopes starting from most deeply nested.
-     *
-     * @param name Name to be looked up
-     * @see #update(String, Node, int)
-     */
-    public Node lookup( String name ) { return update(name,null,_scopes.size()-1);  }
-    /**
-     * If the name is present in any scope, then redefine else null
-     *
-     * @param name Name being redefined
-     * @param n    The node to bind to the name
-     */
-    public Node update( String name, Node n ) { return update(name,n,_scopes.size()-1); }
-    /**
-     * Both recursive lookup and update.
-     * <p>
-     * A shared implementation allows us to create lazy phis both during
-     * lookups and updates; the lazy phi creation is part of chapter 8.
-     *
-     * @param name  Name whose binding is being updated or looked up
-     * @param n     If null, do a lookup, else update binding
-     * @param nestingLevel The starting nesting level
-     * @return node being looked up, or the one that was updated
-     */
-    private Node update( String name, Node n, int nestingLevel ) {
-        if( nestingLevel<0 ) return null;  // Missed in all scopes, not found
-        var syms = _scopes.get(nestingLevel); // Get the symbol table for nesting level
-        var idx = syms.get(name);
-        if( idx == null ) return update(name,n,nestingLevel-1); // Not found in this scope, recursively look in parent scope
-        Node old = in(idx);
-        if( old instanceof ScopeNode loop ) {
-            // Lazy Phi!
-            old = loop.in(idx) instanceof PhiNode phi && loop.ctrl()==phi.region()
-                // Loop already has a real Phi, use it
-                ? loop.in(idx)
-                // Set real Phi in the loop head
-                // The phi takes its one input (no backedge yet) from a recursive
-                // lookup, which might have insert a Phi in every loop nest.
-                : loop.setDef(idx,new PhiNode(name, lookupDeclaredType(name),loop.ctrl(),loop.update(name,null,nestingLevel),null).peephole());
-            setDef(idx,old);
-        }
-        return n==null ? old : setDef(idx,n); // Not lazy, so this is the answer
-    }
-
-    // Return declared type
-    public Type lookupDeclaredType( String name ) {
-        for( int i=_types.size(); i>0; i-- ) {
-            Type t = _types.get(i-1).get(name);
-            if( t != null ) return t;
-        }
-        return null;
-    }
-
-    public Node ctrl() { return in(0); }
-
-    /**
-     * The ctrl of a ScopeNode is always bound to the currently active
-     * control node in the graph, via a special name '$ctrl' that is not
-     * a valid identifier in the language grammar and hence cannot be
-     * referenced in Simple code.
-     *
-     * @param n The node to be bound to '$ctrl'
-     *
-     * @return Node that was bound
-     */
-    public Node ctrl(Node n) { return setDef(0,n); }
-
-    /**
-     * Duplicate a ScopeNode; including all levels, up to Nodes.  So this is
-     * neither shallow (would dup the Scope but not the internal HashMap
-     * tables), nor deep (would dup the Scope, the HashMap tables, but then
-     * also the program Nodes).
-     * <p>
-     * If the {@code loop} flag is set, the edges are filled in as the original
-     * Scope, as a indication of Lazy Phis at loop heads.  The goal here is to
-     * not make Phis at loop heads for variables which are never touched in the
-     * loop body.
-     * <p>
-     * The new Scope is a full-fledged Node with proper use<->def edges.
-     */
-    public ScopeNode dup() { return dup(false); }
-    public ScopeNode dup(boolean loop) {
-        ScopeNode dup = new ScopeNode();
-        // Our goals are:
-        // 1) duplicate the name bindings of the ScopeNode across all stack levels
-        // 2) Make the new ScopeNode a user of all the nodes bound
-        // 3) Ensure that the order of defs is the same to allow easy merging
-        for( HashMap<String,Integer> syms : _scopes )
-            dup._scopes.push(new HashMap<>(syms));
-        for( HashMap<String,Type> ts : _types )
-            dup._types.push(ts); // Types don't change, just keep stacks aligned
-
-        dup.addDef(ctrl());     // Control input is just copied
-        for( int i=1; i<nIns(); i++ )
-            // For lazy phis on loops we use a sentinel
-            // that will trigger phi creation on update
-            dup.addDef(loop ? this : in(i));
-        return dup;
-    }
-
-    /**
-     * Merges the names whose node bindings differ, by creating Phi node for such names
-     * The names could occur at all stack levels, but a given name can only differ in the
-     * innermost stack level where the name is bound.
-     *
-     * @param that The ScopeNode to be merged into this
-     * @return A new node representing the merge point
-     */
-    public Node mergeScopes(ScopeNode that) {
-        RegionNode r = (RegionNode) ctrl(new RegionNode(null,ctrl(), that.ctrl()).keep());
-        String[] ns = reverseNames();
-        // Note that we skip i==0, which is bound to '$ctrl'
-        for (int i = 1; i < nIns(); i++)
-            if( in(i) != that.in(i) ) // No need for redundant Phis
-                // If we are in lazy phi mode we need to a lookup
-                // by name as it will trigger a phi creation
-                setDef(i, new PhiNode(ns[i], this.lookupDeclaredType(ns[i]), r, this.lookup(ns[i]), that.lookup(ns[i])).peephole());
-        that.kill();            // Kill merged scope
-        IterPeeps.add(r);
-        return r.unkeep().peephole();
-    }
-
-    // Merge the backedge scope into this loop head scope
-    // We set the second input to the phi from the back edge (i.e. loop body)
-    public void endLoop(ScopeNode back, ScopeNode exit ) {
-        Node ctrl = ctrl();
-        assert ctrl instanceof LoopNode loop && loop.inProgress();
-        ctrl.setDef(2,back.ctrl());
-        for( int i=1; i<nIns(); i++ ) {
-            if( back.in(i) != this ) {
-                PhiNode phi = (PhiNode)in(i);
-                assert phi.region()==ctrl && phi.in(2)==null;
-                phi.setDef(2,back.in(i));
-            }
-            if( exit.in(i) == this ) // Replace a lazy-phi on the exit path also
-                exit.setDef(i,in(i));
-        }
-        back.kill();            // Loop backedge is dead
-        // Now one-time do a useless-phi removal
-        for( int i=1; i<nIns(); i++ ) {
-            if( in(i) instanceof PhiNode phi ) {
-                // Do an eager useless-phi removal
-                Node in = phi.peephole();
-                IterPeeps.addAll(phi._outputs);
-                phi.moveDepsToWorklist();
-                if( in != phi ) {
-                    if( !phi.iskeep() ) // Keeping phi around for parser elsewhere
-                        phi.subsume(in);
-                    setDef(i,in); // Set the update back into Scope
-                }
-            }
-        }
-
-    }
-
-
-    // Up-casting: using the results of an If to improve a value.
-    // E.g. "if( ptr ) ptr.field;" is legal because ptr is known not-null.
-
-    // This Scope looks for direct variable uses, or certain simple
-    // combinations, and replaces the variable with the upcast variant.
-    public Node upcast( Node ctrl, Node pred, boolean invert ) {
-        if( ctrl._type==Type.XCONTROL ) return null;
-        // A single negation is handled below. For !!p (including p != null),
-        // also refine the underlying p without changing the Boolean result.
-        if( pred instanceof NotNode not && not.in(1) instanceof NotNode ) {
-            pred.keep();        // Recursive peepholes may rediscover this Not.
-            upcast(ctrl,not.in(1),!invert);
-            pred.unkeep();
-        }
-        // Invert the If conditional
-        if( invert )
-            pred = pred instanceof NotNode not ? not.in(1) : IterPeeps.add(new NotNode(pred).peephole());
-
-        // Direct use of a value as predicate.  This is a zero/null test.
-        if( Utils.find(_inputs, pred) != -1 ) {
-            if( !(pred._type instanceof TypeMemPtr tmp) )
-                // Must be an `int`, since int and ptr are the only two value types
-                // being tested. No representation for a generic not-null int, so no upcast.
-                return null;
-            if( tmp.isa(TypeMemPtr.VOIDPTR) )
-                return null;    // Already not-null, no reason to upcast
-            // Upcast the ptr to not-null ptr, and replace in scope
-            return replace(pred,new CastNode(TypeMemPtr.VOIDPTR,ctrl,pred).peephole());
-        }
-
-        if( pred instanceof NotNode not ) {
-            // Direct use of a !value as predicate.  This is a zero/null test.
-            if( Utils.find(_inputs, not.in(1)) != -1 ) {
-                Type tinit = not.in(1)._type.makeInit();
-                if( not.in(1)._type.isa(tinit) ) return null; // Already zero/null, no reason to upcast
-                return replace(not.in(1), new ConstantNode(tinit).peephole());
-            }
-        }
-        // Apr/9/2024: Attempted to replace X with Y if guarded by a test of
-        // X==Y.  This didn't seem to help very much, or at least in the test
-        // cases seen so far was a very minor help.
-
-        // No upcast
-        return null;
-    }
-
-    private Node replace( Node old, Node cast ) {
-        assert old!=null && old!=cast;
-        for( int i=0; i<nIns(); i++ )
-            if( in(i)==old )
-                setDef(i,cast);
-        return cast;
-    }
-
-}
diff --git a/chapter10/src/main/java/com/seaofnodes/simple/node/StartNode.java b/chapter10/src/main/java/com/seaofnodes/simple/node/StartNode.java
deleted file mode 100644
index 4b7e02a8..00000000
--- a/chapter10/src/main/java/com/seaofnodes/simple/node/StartNode.java
+++ /dev/null
@@ -1,78 +0,0 @@
-package com.seaofnodes.simple.node;
-
-import com.seaofnodes.simple.Parser;
-import com.seaofnodes.simple.type.*;
-import java.util.Arrays;
-import java.util.BitSet;
-import java.util.HashMap;
-
-/**
- * The Start node represents the start of the function.
- *
- * Start initially has 1 input (arg) from outside and the initial control.
- * In ch10 we also add mem aliases as structs get defined; each field in struct
- * adds a distinct alias to Start's tuple.
- */
-public class StartNode extends MultiNode {
-
-    // This field is NOT final, because the tuple expands as we add memory aliases
-    TypeTuple _args;
-
-    // The alias number of the first field in the struct.
-    //
-    public final HashMap<String,Integer> _aliasStarts;
-
-
-    public StartNode(Type[] args) {
-        super();
-        _args = TypeTuple.make(args);
-        _type = _args;
-        _aliasStarts = new HashMap<>();
-    }
-
-    /**
-     * Creates a projection for each of the struct's fields, using the field alias
-     * as the key.
-     */
-    public void addMemProj( TypeStruct ts, ScopeNode scope) {
-        int len = _args._types.length;
-        _aliasStarts.put(ts._name,len);
-
-        // resize the tuple's type array to include all fields of the struct
-        int max = len + ts._fields.length;
-        Type[] args = Arrays.copyOf(_args._types, max);
-
-        // The new members of the tuple get a mem type with an alias
-        for( int alias = len; alias < max; alias++ )
-            args[alias] = TypeMem.make(alias);
-        _type = _args = TypeTuple.make(args);
-        // For each of the fields we now add a mem projection.  Note that the
-        // alias matches the slot of the field in the tuple
-        for( int alias = len; alias < max; alias++ ) {
-            String name = Parser.memName(alias);
-            Node n = new ProjNode(this, alias, name).peephole();
-            scope.define(name, args[alias], n);
-        }
-    }
-
-    @Override
-    public String label() { return "Start"; }
-
-    @Override
-    StringBuilder _print1(StringBuilder sb, BitSet visited) {
-      return sb.append(label());
-    }
-
-    @Override public boolean isCFG() { return true; }
-    @Override public boolean isMultiHead() { return true; }
-
-    @Override
-    public TypeTuple compute() { return _args; }
-
-    @Override
-    public Node idealize() { return null; }
-
-    // No immediate dominator, and idepth==0
-    @Override int idepth() { return 0; }
-    @Override Node idom() { return null; }
-}
diff --git a/chapter10/src/main/java/com/seaofnodes/simple/node/StopNode.java b/chapter10/src/main/java/com/seaofnodes/simple/node/StopNode.java
deleted file mode 100644
index cb4126f5..00000000
--- a/chapter10/src/main/java/com/seaofnodes/simple/node/StopNode.java
+++ /dev/null
@@ -1,74 +0,0 @@
-package com.seaofnodes.simple.node;
-
-import com.seaofnodes.simple.Parser;
-
-import com.seaofnodes.simple.type.Type;
-import com.seaofnodes.simple.IterPeeps;
-
-import java.util.BitSet;
-
-public class StopNode extends Node {
-
-    public final String _src;
-
-    public StopNode(String src) {
-        super();
-        _src = src;
-    }
-
-    @Override
-    public String label() {
-        return "Stop";
-    }
-
-    @Override
-    StringBuilder _print1(StringBuilder sb, BitSet visited) {
-        if( ret()!=null ) return ret()._print0(sb, visited);
-        sb.append("Stop[ ");
-        for( Node ret : _inputs )
-            ret._print0(sb, visited).append(" ");
-        return sb.append("]");
-    }
-
-    @Override public boolean isCFG() { return true; }
-
-    // If a single Return, return it.
-    // Otherwise, null because ambiguous.
-    public ReturnNode ret() {
-        return nIns()==1 ? (ReturnNode)in(0) : null;
-    }
-
-    @Override
-    public Type compute() {
-        return Type.BOTTOM;
-    }
-
-    @Override
-    public Node idealize() {
-        int len = nIns();
-        for( int i=0; i<nIns(); i++ )
-            if( in(i)._type==Type.XCONTROL )
-                delDef(i--);
-        if( len != nIns() ) return this;
-        return null;
-    }
-
-    @Override public Node idom() { return null; }
-
-    public Node addReturn(Node node) {
-        return addDef(node);
-    }
-
-    public StopNode iterate() { return IterPeeps.iterate(this).typeCheck(); }
-    public StopNode typeCheck() {
-        var obs = Parser.PARSER == null ? null : Parser.PARSER._obs;
-        String err = walk(n -> {
-            String msg = n.err();
-            if( msg != null && obs != null ) obs.error(n, msg);
-            return msg;
-        });
-        if( err != null ) throw new RuntimeException(err);
-        if( obs != null ) obs.phase("TypeCheck");
-        return this;
-    }
-}
diff --git a/chapter10/src/main/java/com/seaofnodes/simple/node/StoreNode.java b/chapter10/src/main/java/com/seaofnodes/simple/node/StoreNode.java
deleted file mode 100644
index cf586d6e..00000000
--- a/chapter10/src/main/java/com/seaofnodes/simple/node/StoreNode.java
+++ /dev/null
@@ -1,68 +0,0 @@
-package com.seaofnodes.simple.node;
-
-import com.seaofnodes.simple.Utils;
-import com.seaofnodes.simple.type.*;
-
-import java.util.BitSet;
-
-/**
- * Store represents setting a value to a memory based object, in chapter 10
- * this means a field inside a struct.
- */
-public class StoreNode extends MemOpNode {
-
-    /**
-     * @param name The struct field we are assigning to
-     * @param memSlice The memory alias node - this is updated after a Store
-     * @param memPtr The ptr to the struct where we will store a value
-     * @param value Value to be stored
-     */
-    public StoreNode(String name, int alias, Node memSlice, Node memPtr, Node value) {
-        super(name, alias, memSlice, memPtr, value);
-    }
-
-    @Override
-    public String label() { return "Store"; }
-    @Override
-    public boolean isMem() { return true; }
-    public Node val() { return in(3); }
-
-    @Override
-    StringBuilder _print1(StringBuilder sb, BitSet visited) {
-        return sb.append(".").append(_name).append("=").append( val()).append(";");
-    }
-
-    @Override
-    public Type compute() { return TypeMem.make(_alias); }
-
-    @Override
-    public Node idealize() {
-
-        // Simple store-after-store on same address.  Should pick up the
-        // required init-store being stomped by a first user store.
-        if( mem() instanceof StoreNode st &&
-            ptr()==st.ptr() &&  // Must check same object
-            ptr()._type instanceof TypeMemPtr && // No bother if weird dead pointers
-            // Must have exactly one use of "this" or you get weird
-            // non-serializable memory effects in the worse case.
-            st.checkNoUseBeyond(this) ) {
-            assert Utils.eq(_name,st._name); // Equiv class aliasing is perfect
-            setDef(1,st.mem());
-            return this;
-        }
-
-        return null;
-    }
-
-    // Check that `this` has no uses beyond `that`
-    private boolean checkNoUseBeyond(Node that) {
-        if( nOuts()==1 ) return true;
-        // Add deps on the other uses (can be e.g. ScopeNode mid-parse) so that
-        // when the other uses go away we can retry.
-        for( Node use : _outputs )
-            if( use != that )
-                use.addDep(that);
-        return false;
-    }
-
-}
diff --git a/chapter10/src/main/java/com/seaofnodes/simple/node/SubNode.java b/chapter10/src/main/java/com/seaofnodes/simple/node/SubNode.java
deleted file mode 100644
index eeec5e1d..00000000
--- a/chapter10/src/main/java/com/seaofnodes/simple/node/SubNode.java
+++ /dev/null
@@ -1,63 +0,0 @@
-package com.seaofnodes.simple.node;
-
-import com.seaofnodes.simple.type.Type;
-import com.seaofnodes.simple.type.TypeInteger;
-
-import java.util.BitSet;
-
-public class SubNode extends Node {
-    public SubNode(Node lhs, Node rhs) { super(null, lhs, rhs); }
-
-    @Override public String label() { return "Sub"; }
-
-    @Override
-    StringBuilder _print1(StringBuilder sb, BitSet visited) {
-        in(1)._print0(sb.append("("), visited);
-        in(2)._print0(sb.append("-"), visited);
-        return sb.append(")");
-    }
-
-    @Override
-    public Type compute() {
-        Type t1 = in(1)._type, t2 = in(2)._type;
-        if( t1==Type.TOP || t1==TypeInteger.TOP ||
-            t2==Type.TOP || t2==TypeInteger.TOP )
-            return TypeInteger.TOP;
-        // Sub of same is 0
-        if( in(1)==in(2) )
-            return TypeInteger.ZERO;
-
-        if (t1 instanceof TypeInteger i0 &&
-            t2 instanceof TypeInteger i1) {
-            if (i0.isConstant() && i1.isConstant())
-                return TypeInteger.constant(i0.value()-i1.value());
-        }
-        return TypeInteger.BOT;
-    }
-
-    @Override
-    public Node idealize() {
-        Node lhs = in(1);
-        Node rhs = in(2);
-        Type t1 = lhs._type;
-        Type t2 = rhs._type;
-
-        // Keep invalid operands for type checking.
-        if( t1 instanceof TypeInteger x && t2 instanceof TypeInteger y ) {
-            if( y.isConstant() && y.value()==0 ) return lhs;
-            if( x.isConstant() && x.value()==0 ) return new MinusNode(rhs);
-        }
-
-        // x - (-y) is x+y
-        if( rhs instanceof MinusNode minus )
-            return new AddNode(lhs,minus.in(1));
-
-        // (-x) - y is -(x+y)
-        if( lhs instanceof MinusNode minus )
-            return new MinusNode(new AddNode(minus.in(1),rhs).peephole());
-
-        return null;
-    }
-
-    @Override Node copy(Node lhs, Node rhs) { return new SubNode(lhs,rhs); }
-}
diff --git a/chapter10/src/main/java/com/seaofnodes/simple/print/SimpleGraphAdapter.java b/chapter10/src/main/java/com/seaofnodes/simple/print/SimpleGraphAdapter.java
deleted file mode 100644
index 600e9c73..00000000
--- a/chapter10/src/main/java/com/seaofnodes/simple/print/SimpleGraphAdapter.java
+++ /dev/null
@@ -1,62 +0,0 @@
-package com.seaofnodes.simple.print;
-
-import com.seaofnodes.graph.GraphAdapter;
-import com.seaofnodes.graph.GraphSnapshot;
-import com.seaofnodes.graph.GraphSnapshot.*;
-import com.seaofnodes.simple.node.*;
-import com.seaofnodes.simple.node.Node;
-import com.seaofnodes.simple.type.TypeMem;
-import java.util.ArrayList;
-
-/** Chapter 10's view of the IR; browser, transport and layout are shared. */
-public class SimpleGraphAdapter extends GraphAdapter<Node> {
-    @Override protected boolean dead(Node n) { return n.isDead(); }
-    @Override protected int id(Node n) { return n._nid; }
-    @Override protected int nIns(Node n) { return n.nIns(); }
-    @Override protected Node in(Node n, int idx) { return n.in(idx); }
-    @Override protected int nOuts(Node n) { return n.nOuts(); }
-    @Override protected Node out(Node n, int idx) { return n.out(idx); }
-    @Override protected int nDeps(Node n) { return n.nDeps(); }
-    @Override protected Node dep(Node n, int idx) { return n.dep(idx); }
-
-    private ArrayList<Edge> edges(Node n) {
-        var edges = new ArrayList<Edge>();
-        String[] names = n instanceof ScopeNode scope && n.nIns() != 0 ? scope.reverseNames() : null;
-        for( int i = 0; i < n.nIns(); i++ ) {
-            String name = names == null || i >= names.length ? null : names[i];
-            edges.add(new Edge(i, ref(n.in(i)), role(n, i), name));
-        }
-        return edges;
-    }
-
-    @Override protected GraphSnapshot.Node desc(Node n) {
-        Projection proj = n instanceof ProjNode p ? new Projection(ref(n.in(0)), p._idx) : null;
-        String label = n.label();
-        return new GraphSnapshot.Node(n._nid, label == null ? n.getClass().getSimpleName() : label,
-                                      n._type == null ? null : n._type.toString(), kind(n), edges(n), proj);
-    }
-
-    private Kind kind(Node n) {
-        if( n instanceof StopNode ) return Kind.STOP;
-        if( n instanceof ScopeNode ) return Kind.SCOPE;
-        if( n instanceof StartNode ) return Kind.CTRL;
-        if( n instanceof LoopNode ) return Kind.LOOP;
-        if( n instanceof RegionNode ) return Kind.REGION;
-        if( n instanceof PhiNode ) return Kind.PHI;
-        return n.isCFG() ? Kind.CTRL : isMem(n) ? Kind.MEM : Kind.DATA;
-    }
-
-    private Role role(Node n, int i) {
-        if( n instanceof ScopeNode || n instanceof ConstantNode ) return Role.ASSOC;
-        if( n instanceof PhiNode ) return i == 0 ? Role.ASSOC : isMem(n) ? Role.MEM : Role.DATA;
-        if( n instanceof ProjNode ) return n.isCFG() ? Role.CTRL : isMem(n) ? Role.MEM : Role.DATA;
-        if( n instanceof RegionNode && i == 0 ) return Role.ASSOC;
-        if( i == 0 || n instanceof RegionNode || n instanceof StopNode ) return Role.CTRL;
-        if( i == 1 && (n instanceof MemOpNode || n instanceof ReturnNode) ) return Role.MEM;
-        Node def = n.in(i);
-        if( def != null && isMem(def) ) return Role.MEM;
-        return Role.DATA;
-    }
-
-    private boolean isMem(Node n) { return n.isMem() || n._type instanceof TypeMem; }
-}
diff --git a/chapter10/src/main/java/com/seaofnodes/simple/print/SimpleGraphObserver.java b/chapter10/src/main/java/com/seaofnodes/simple/print/SimpleGraphObserver.java
deleted file mode 100644
index 1980659e..00000000
--- a/chapter10/src/main/java/com/seaofnodes/simple/print/SimpleGraphObserver.java
+++ /dev/null
@@ -1,45 +0,0 @@
-package com.seaofnodes.simple.print;
-
-import com.seaofnodes.graph.GraphCapture;
-import com.seaofnodes.graph.GraphViewer;
-import com.seaofnodes.simple.Parser;
-import com.seaofnodes.simple.node.Node;
-import java.util.ArrayList;
-import java.io.IOException;
-
-/** Chapter 10's compilation context; capture and event bookkeeping are shared. */
-public class SimpleGraphObserver extends GraphCapture<Node> {
-    private Parser _parser;
-    private Node _ret;
-    private String _phase;
-    public SimpleGraphObserver() { super(new SimpleGraphAdapter()); }
-    public static void main(String[] args) throws IOException {
-        GraphViewer.run(new SimpleGraphObserver());
-    }
-    @Override protected void compile(String src) {
-        _parser = new Parser(src);
-        _parser._obs = this;
-        _phase = "Parse";
-        _ret = _parser.parse();
-        phase(_phase);
-        _phase = "Iter";
-        com.seaofnodes.simple.IterPeeps.iterate(_parser.STOP);
-        phase(_phase);
-        _phase = "TypeCheck";
-        _parser.STOP.typeCheck();
-    }
-    @Override protected String phase() { return _phase; }
-    @Override protected int pos() { return "Parse".equals(_phase) ? _parser.pos() : -1; }
-    @Override protected void detach() {
-        if( _parser != null ) _parser._obs = null;
-        _parser = null;
-        _ret = null;
-    }
-    @Override protected Node scope() { return _parser._scope; }
-    @Override protected void roots(ArrayList<Node> roots) {
-        roots.add(Parser.START);
-        roots.add(_parser.STOP);
-        roots.addAll(_parser._xScopes);
-        roots.add(_ret);
-    }
-}
diff --git a/chapter10/src/main/java/com/seaofnodes/simple/type/Field.java b/chapter10/src/main/java/com/seaofnodes/simple/type/Field.java
deleted file mode 100644
index 96088f90..00000000
--- a/chapter10/src/main/java/com/seaofnodes/simple/type/Field.java
+++ /dev/null
@@ -1,60 +0,0 @@
-package com.seaofnodes.simple.type;
-
-import com.seaofnodes.simple.Utils;
-import java.util.ArrayList;
-
-/**
- * Represents a field in a struct. This is not a Type in the type system.
- */
-public class Field extends Type {
-
-    // The pair {fieldName,type} uniquely identifies a field.
-
-    // Field name
-    public final String _fname;
-    // Type of the field
-    public final Type _type;
-
-    private Field(String fname, Type type ) {
-        super(TFLD);
-        _fname = fname;
-        _type  = type;
-    }
-    // Make with existing alias
-    public static Field make( String fname, Type type ) {
-        return new Field(fname,type).intern();
-    }
-
-    public static final Field TEST = make("test",TypeInteger.ZERO);
-    public static void gather(ArrayList<Type> ts) { ts.add(TEST); }
-
-    @Override Field xmeet( Type that ) {
-        Field fld = (Field)that; // Invariant
-        assert _fname.equals(fld._fname);
-        return make(_fname,_type.meet(fld._type));
-    }
-
-    @Override
-    public Field dual() { return make(_fname,_type.dual()); }
-
-    @Override
-    public Field glb() {
-        return make(_fname,_type.glb());
-    }
-
-    // Override in subclasses
-    int hash() { return _fname.hashCode() ^ _type.hashCode(); }
-
-    boolean eq(Type t) {
-        Field f = (Field)t;
-        return Utils.eq(_fname,f._fname) && _type==f._type;
-    }
-
-
-    @Override
-    public StringBuilder print( StringBuilder sb ) {
-        return _type.print(sb.append(_fname).append(":"));
-    }
-
-    @Override public String str() { return _fname; }
-}
diff --git a/chapter10/src/main/java/com/seaofnodes/simple/type/Type.java b/chapter10/src/main/java/com/seaofnodes/simple/type/Type.java
deleted file mode 100644
index 93e27c76..00000000
--- a/chapter10/src/main/java/com/seaofnodes/simple/type/Type.java
+++ /dev/null
@@ -1,187 +0,0 @@
-package com.seaofnodes.simple.type;
-
-import com.seaofnodes.simple.Utils;
-
-import java.util.ArrayList;
-import java.util.HashMap;
-
-/**
- * These types are part of a Monotone Analysis Framework,
- * @see <a href="https://www.cse.psu.edu/~gxt29/teaching/cse597s21/slides/08monotoneFramework.pdf">see for example this set of slides</a>.
- * <p>
- * The types form a lattice; @see <a href="https://en.wikipedia.org/wiki/Lattice_(order)">a symmetric complete bounded (ranked) lattice.</a>
- * <p>
- * This wild lattice theory will be needed later to allow us to easily beef up
- * the analysis and optimization of the Simple compiler... but we don't need it
- * now, just know that it is coming along in a later Chapter.
- * <p>g
- * One of the fun things here is that while the theory is deep and subtle, the
- * actual implementation is darn near trivial and is generally really obvious
- * what we're doing with it.  Right now, it's just simple integer math to do
- * simple constant folding e.g. 1+2 == 3 stuff.
- */
-
-public class Type {
-    static final HashMap<Type,Type> INTERN = new HashMap<>();
-
-    // ----------------------------------------------------------
-    // Simple types are implemented fully here.  "Simple" means: the code and
-    // type hierarchy are simple, not that the Type is conceptually simple.
-    static final byte TBOT    = 0; // Bottom (ALL)
-    static final byte TTOP    = 1; // Top    (ANY)
-    static final byte TCTRL   = 2; // Ctrl flow bottom
-    static final byte TXCTRL  = 3; // Ctrl flow top (mini-lattice: any-xctrl-ctrl-all)
-    static final byte TSIMPLE = 4; // End of the Simple Types
-    static final byte TINT    = 5; // All Integers; see TypeInteger
-    static final byte TTUPLE  = 6; // Tuples; finite collections of unrelated Types, kept in parallel
-    static final byte TMEM    = 7; // All memory (alias 0) or A slice of memory - with specific alias
-    static final byte TMEMPTR = 8; // Memory pointer type
-    static final byte TSTRUCT = 9; // Structs; tuples with named fields
-    static final byte TFLD    =10; // Fields into struct
-
-    public final byte _type;
-
-    public boolean is_simple() { return _type < TSIMPLE; }
-    private static final String[] STRS = new String[]{"Bot","Top","Ctrl","~Ctrl"};
-    protected Type(byte type) { _type = type; }
-
-    public static final Type BOTTOM   = new Type( TBOT   ).intern(); // ALL
-    public static final Type TOP      = new Type( TTOP   ).intern(); // ANY
-    public static final Type CONTROL  = new Type( TCTRL  ).intern(); // Ctrl
-    public static final Type XCONTROL = new Type( TXCTRL ).intern(); // ~Ctrl
-    public static Type[] gather() {
-        ArrayList<Type> ts = new ArrayList<>();
-        ts.add(BOTTOM);
-        ts.add(CONTROL);
-        Field.gather(ts);
-        TypeInteger.gather(ts);
-        TypeMem.gather(ts);
-        TypeMemPtr.gather(ts);
-        TypeStruct.gather(ts);
-        TypeTuple.gather(ts);
-        int sz = ts.size();
-        for( int i = 0; i < sz; i++ )
-            ts.add(ts.get(i).dual());
-        return ts.toArray(new Type[ts.size()]);
-    }
-
-    // Is high or on the lattice centerline.
-    public boolean isHighOrConst() { return _type==TTOP || _type==TXCTRL; }
-
-    // Strict constant values, things on the lattice centerline.
-    // Excludes both high and low values
-    public boolean isConstant() { return false; }
-
-    /**
-     * Display Type name in a format that's good for IR printer
-     */
-    public StringBuilder typeName( StringBuilder sb) { return print(sb); }
-
-    public Type makeInit() { return null; }
-
-    // ----------------------------------------------------------
-
-    // Notes on Type interning.
-    // At the moment it is not easy to reset the interned types
-    // because we hold static references to several types and these are scattered
-    // around. This means the INTERN cache will retain all types from
-    // every run of the Parser. For this to work correctly types must be
-    // rigorous about defining when they are the same. Also types need to be
-    // immutable once defined.
-    // The rationale for interning is performance.
-
-    // Factory method which interns "this"
-    public  <T extends Type> T intern() {
-        T nnn = (T)INTERN.get(this);
-        if( nnn==null )
-            INTERN.put(nnn=(T)this,this);
-        return nnn;
-    }
-
-    private int _hash;          // Hash cache; not-zero when set.
-    @Override
-    public final int hashCode() {
-        if( _hash!=0 ) return _hash;
-        _hash = hash();
-        if( _hash==0 ) _hash = 0xDEADBEEF; // Bad hash from subclass; use some junk thing
-        return _hash;
-    }
-    // Override in subclasses
-    int hash() { return _type; }
-
-    @Override
-    public final boolean equals( Object o ) {
-        if( o==this ) return true;
-        if( !(o instanceof Type t)) return false;
-        if( _type != t._type ) return false;
-        return eq(t);
-    }
-    // Overridden in subclasses; subclass can assume "this!=t" and java classes are same
-    boolean eq(Type t) { return true; }
-
-
-    // ----------------------------------------------------------
-    public final Type meet(Type t) {
-        // Shortcut for the self case
-        if( t == this ) return this;
-        // Same-type is always safe in the subclasses
-        if( _type==t._type ) return xmeet(t);
-        // Reverse; xmeet 2nd arg is never "is_simple" and never equal to "this".
-        if(   is_simple() ) return this.xmeet(t   );
-        if( t.is_simple() ) return t   .xmeet(this);
-        return Type.BOTTOM;     // Mixing 2 unrelated types
-    }
-
-    // Compute meet right now.  Overridden in subclasses.
-    // Handle cases where 'this.is_simple()' and unequal to 't'.
-    // Subclassed xmeet calls can assert that '!t.is_simple()'.
-    Type xmeet(Type t) {
-        assert is_simple(); // Should be overridden in subclass
-        // ANY meet anything is thing; thing meet ALL is ALL
-        if( _type==TBOT || t._type==TTOP ) return this;
-        if( _type==TTOP || t._type==TBOT ) return    t;
-        // 'this' is {TCTRL,TXCTRL}
-        if( !t.is_simple() ) return BOTTOM;
-        // 't' is {TCTRL,TXCTRL}
-        return _type==TCTRL || t._type==TCTRL ? CONTROL : XCONTROL;
-    }
-
-    public Type dual() {
-        return switch( _type ) {
-        case TBOT -> TOP;
-        case TTOP -> BOTTOM;
-        case TCTRL -> XCONTROL;
-        case TXCTRL -> CONTROL;
-        default -> throw Utils.TODO(); // Should not reach here
-        };
-    }
-
-    // ----------------------------------------------------------
-    // Our lattice is defined with a MEET and a DUAL.
-    // JOIN is dual of meet of both duals.
-    public final Type join(Type t) {
-        if( this==t ) return this;
-        return dual().meet(t.dual()).dual();
-    }
-
-    // True if this "isa" t; e.g. 17 isa TypeInteger.BOT
-    public boolean isa( Type t ) { return meet(t)==t; }
-
-    /**
-     * Compute greatest lower bound in the lattice
-     */
-    public Type glb() { return _type==TCTRL ? XCONTROL : BOTTOM; }
-
-    // ----------------------------------------------------------
-    // Useful in the debugger, which calls toString everywhere.
-    // This is a more verbose dev-friendly print.
-    @Override
-    public final String toString() {
-        return print(new StringBuilder()).toString();
-    }
-
-    public StringBuilder print(StringBuilder sb) { return is_simple() ? sb.append(STRS[_type]) : sb;}
-
-    // This is used by error messages, and is a shorted print.
-    public String str() { return STRS[_type]; }
-}
diff --git a/chapter10/src/main/java/com/seaofnodes/simple/type/TypeInteger.java b/chapter10/src/main/java/com/seaofnodes/simple/type/TypeInteger.java
deleted file mode 100644
index 8c77672b..00000000
--- a/chapter10/src/main/java/com/seaofnodes/simple/type/TypeInteger.java
+++ /dev/null
@@ -1,101 +0,0 @@
-package com.seaofnodes.simple.type;
-
-import java.util.ArrayList;
-
-/**
- * Integer Type
- */
-public class TypeInteger extends Type {
-
-    public final static TypeInteger TOP = make(false, 0);
-    public final static TypeInteger BOT = make(false, 1);
-    public final static TypeInteger ZERO= make(true , 0);
-
-    public final boolean _is_con;
-
-    /**
-     * The constant value or
-     * if not constant then 1=bottom, 0=top.
-     */
-    public final long _con;
-
-    private TypeInteger(boolean is_con, long con) {
-        super(TINT);
-        _is_con = is_con;
-        _con = con;
-    }
-    public static TypeInteger make(boolean is_con, long con) {
-        return new TypeInteger(is_con,con).intern();
-    }
-
-    public static TypeInteger constant(long con) { return make(true, con); }
-
-    public static void gather(ArrayList<Type> ts) { ts.add(ZERO); ts.add(BOT); }
-
-    // FIXME this display format is problematic
-    // In visualizer '#' gets prepended if its a constant
-    @Override
-    public StringBuilder print(StringBuilder sb) {
-        if( this==TOP ) return sb.append("IntTop");
-        if( this==BOT ) return sb.append("IntBot");
-        return sb.append(_con);
-    }
-
-    @Override public String str() {
-        if( this==TOP ) return "~int";
-        if( this==BOT ) return  "int";
-        return ""+_con;
-    }
-
-    /**
-     * Display Type name in a format that's good for IR printer
-     */
-    @Override
-    public StringBuilder typeName(StringBuilder sb) {
-        if( this==TOP ) return sb.append("IntTop");
-        if( this==BOT ) return sb.append("IntBot");
-        return sb.append("Int");
-    }
-
-    @Override
-    public boolean isHighOrConst() { return _is_con || _con==0; }
-
-    @Override
-    public boolean isConstant() { return _is_con; }
-
-    public long value() { return _con; }
-
-    @Override
-    public Type xmeet(Type other) {
-        // Invariant from caller: 'this' != 'other' and same class (TypeInteger)
-        TypeInteger i = (TypeInteger)other; // Contract
-        // BOT wins
-        if ( this==BOT ) return this;
-        if ( i   ==BOT ) return i   ;
-        // TOP loses
-        if ( i   ==TOP ) return this;
-        if ( this==TOP ) return i   ;
-        // Since both are constants, and are never equals (contract) unequals
-        // constants fall to bottom
-        return BOT;
-    }
-
-    @Override
-    public Type dual() {
-        if( isConstant() ) return this; // Constants are a self-dual
-        return _con==0 ? BOT : TOP;
-    }
-
-    @Override
-    public Type glb() { return BOT; }
-
-    @Override public TypeInteger makeInit() { return ZERO; }
-
-    @Override
-    int hash() { return (int)(_con ^ (_is_con ? 0 : 0x4000)); }
-    @Override
-    public boolean eq( Type t ) {
-        TypeInteger i = (TypeInteger)t; // Contract
-        return _con==i._con && _is_con==i._is_con;
-    }
-}
diff --git a/chapter10/src/main/java/com/seaofnodes/simple/type/TypeMem.java b/chapter10/src/main/java/com/seaofnodes/simple/type/TypeMem.java
deleted file mode 100644
index b6fc8824..00000000
--- a/chapter10/src/main/java/com/seaofnodes/simple/type/TypeMem.java
+++ /dev/null
@@ -1,66 +0,0 @@
-package com.seaofnodes.simple.type;
-
-import com.seaofnodes.simple.Utils;
-import java.lang.Long;
-import java.util.BitSet;
-import java.util.ArrayList;
-
-
-/**
- * Represents a slice of memory corresponding to a set of aliases
- */
-public class TypeMem extends Type {
-
-    // Which slice of memory?
-    //  0 means TOP, no slice.
-    // -1 means BOT, all memory.
-    //  N means slice#N.
-    private final int _alias;
-
-    private TypeMem(int alias) { super(TMEM); _alias = alias; }
-
-    public static TypeMem make(int alias) { return new TypeMem(alias).intern(); }
-    public static final TypeMem TOP = make( 0);
-    public static final TypeMem BOT = make(-1);
-
-
-    public static void gather(ArrayList<Type> ts) { ts.add(make(1)); ts.add(BOT); }
-
-    @Override
-    TypeMem xmeet(Type t) {
-        TypeMem that = (TypeMem) t; // Invariant: TypeMem and unequal
-        return _alias==0 ? that : (that._alias==0 ? this : BOT);
-    }
-
-    @Override
-    public Type dual() {
-        if( _alias== 0 ) return BOT;
-        if( _alias==-1 ) return TOP;
-        return this;
-    }
-
-    @Override
-    public Type glb() { return TypeMem.BOT; }
-
-    @Override
-    int hash() { return 9876543 + _alias; }
-
-    @Override
-    boolean eq(Type t) {
-        TypeMem that = (TypeMem) t; // Invariant
-        return _alias == that._alias;
-    }
-
-    @Override
-    public StringBuilder print(StringBuilder sb) {
-        if( this==BOT ) return sb.append("MemBot");
-        if( this==TOP ) return sb.append("MemTop");
-        return sb.append("MEM#").append( switch(_alias) {
-            case  0 -> "TOP";
-            case -1 -> "BOT";
-            default -> ""+_alias;
-            });
-    }
-
-    @Override public String str() { return print(new StringBuilder()).toString(); }
-}
diff --git a/chapter10/src/main/java/com/seaofnodes/simple/type/TypeMemPtr.java b/chapter10/src/main/java/com/seaofnodes/simple/type/TypeMemPtr.java
deleted file mode 100644
index 6c874a93..00000000
--- a/chapter10/src/main/java/com/seaofnodes/simple/type/TypeMemPtr.java
+++ /dev/null
@@ -1,82 +0,0 @@
-package com.seaofnodes.simple.type;
-
-import java.util.ArrayList;
-
-/**
- * Represents a Pointer to memory.
- *
- * Null is generic pointer to non-existent memory.
- * *void is a non-Null pointer to all possible structs.
- * Pointers can be to specific struct types, or a union with Null.
- * The distinguished *$BOT ptr represents union of *void and Null.
- * The distinguished *$TOP ptr represents the dual of *$BOT.
- */
-public class TypeMemPtr extends Type {
-    // A TypeMemPtr is pair (obj,nil)
-    // where obj is one of
-    //    (null,TypeStruct).
-    // where nil is one of
-    //    (true,false) meaning an explicit null is allowed or not
-
-    public final TypeStruct _obj; // null, a TypeStruct, or sentinel TypeStruct.MANY
-    public final boolean _nil;
-
-    private TypeMemPtr(TypeStruct obj, boolean nil) {
-        super(TMEMPTR);
-        _obj = obj;
-        _nil = nil;
-    }
-    public static TypeMemPtr make(TypeStruct obj, boolean nil) { return new TypeMemPtr(obj, nil).intern(); }
-    public static TypeMemPtr make(TypeStruct obj) { return TypeMemPtr.make(obj, false); }
-
-    public static final TypeMemPtr BOT = make(TypeStruct.BOT,true);
-    public static final TypeMemPtr TOP = BOT.dual();
-    public static final TypeMemPtr NULLPTR = make(TypeStruct.TOP,true);
-    public static final TypeMemPtr VOIDPTR = NULLPTR.dual(); // A bottom mix of not-null ptrs, like C's void* but not null
-    public static final TypeMemPtr TEST= make(TypeStruct.TEST,false);
-    public static void gather(ArrayList<Type> ts) { ts.add(NULLPTR); ts.add(BOT); ts.add(TEST); }
-
-    @Override
-    Type xmeet(Type t) {
-        TypeMemPtr that = (TypeMemPtr) t;
-        return TypeMemPtr.make((TypeStruct)_obj.meet(that._obj), _nil | that._nil);
-    }
-
-    @Override
-    public TypeMemPtr dual() { return TypeMemPtr.make(_obj==null ? null : _obj.dual(), !_nil); }
-
-    @Override
-    public Type glb() {
-        if( _obj==null ) return BOT;
-        return make(_obj.glb(),true);
-    }
-    @Override public TypeMemPtr makeInit() { return NULLPTR; }
-
-    @Override
-    int hash() { return (_obj==null ? 0xDEADBEEF : _obj.hashCode()) ^ (_nil ? 1024 : 0); }
-
-    @Override
-    boolean eq(Type t) {
-        TypeMemPtr ptr = (TypeMemPtr)t; // Invariant
-        return _obj == ptr._obj  && _nil == ptr._nil;
-    }
-
-    // [void,name,MANY]*[,?]
-    @Override
-    public StringBuilder print(StringBuilder sb) {
-        if( this==BOT ) return sb.append("PtrBot");
-        if( this==TOP ) return sb.append("PtrTop");
-        if( this== NULLPTR) return sb.append("null");
-        if( this== VOIDPTR) return sb.append("*void");
-        return _obj.print(sb.append("*")).append(_nil ? "?" : "");
-    }
-
-    @Override public String str() {
-        if( this==BOT ) return "PtrBot";
-        if( this==TOP ) return "PtrTop";
-        if( this== NULLPTR) return "null";
-        if( this== VOIDPTR) return "*void";
-        return "*"+_obj.str()+(_nil ? "?" : "");
-    }
-
-}
diff --git a/chapter10/src/main/java/com/seaofnodes/simple/type/TypeStruct.java b/chapter10/src/main/java/com/seaofnodes/simple/type/TypeStruct.java
deleted file mode 100644
index 44741def..00000000
--- a/chapter10/src/main/java/com/seaofnodes/simple/type/TypeStruct.java
+++ /dev/null
@@ -1,127 +0,0 @@
-package com.seaofnodes.simple.type;
-
-import com.seaofnodes.simple.Utils;
-import java.util.ArrayList;
-
-/**
- * Represents a struct type.
- */
-public class TypeStruct extends Type {
-
-    // For now in terms of the lattice
-    // a struct type just stays as is
-
-    public final String _name;
-    public final Field[] _fields;
-
-    private TypeStruct(String name, Field[] fields) {
-        super(Type.TSTRUCT);
-        _name = name;
-        _fields = fields;
-    }
-
-    public static TypeStruct make(String name, Field[] fields) { return new TypeStruct(name, fields).intern(); }
-    public static TypeStruct make(String name, ArrayList<Field> fields) { return make(name,fields.toArray(new Field[fields.size()])); }
-
-    public static final TypeStruct TOP = make("$TOP",new Field [0]);
-    public static final TypeStruct BOT = make("$BOT",new Field [0]);
-    public static final TypeStruct TEST = make("test",new Field[]{Field.TEST});
-    public static void gather(ArrayList<Type> ts) { ts.add(TEST); ts.add(BOT); }
-
-    public int find(String fname) {
-        for( int i=0; i<_fields.length; i++ )
-            if( _fields[i]._fname.equals(fname) )
-                return i;
-        return -1;
-    }
-
-    @Override
-    Type xmeet(Type t) {
-        TypeStruct that = (TypeStruct) t;
-        if( this==TOP ) return that;
-        if( that==TOP ) return this;
-        if( this==BOT ) return BOT;
-        if( that==BOT ) return BOT;
-
-        // Within the same compilation unit, struct names are unique.  If the
-        // names differ, its different structs.  Across many compilation units,
-        // structs with the same name but different field layouts can be
-        // interned... which begs the question:
-        // "What is the meet of structs from two different compilation units?"
-        // And the answer is: "don't ask".
-        if( !_name.equals(that._name) )
-            return BOT;         // It's a struct; that's about all we know
-        // Now all fields should be the same, so just do field meets
-        assert _fields.length == that._fields.length;
-        Field[] flds = new Field[_fields.length];
-        for( int i=0; i<_fields.length; i++ )
-            flds[i] = (Field)_fields[i].meet(that._fields[i]);
-        return make(_name,flds);
-    }
-
-    @Override
-    public TypeStruct dual() {
-        if( this==TOP ) return BOT;
-        if( this==BOT ) return TOP;
-        Field[] flds = new Field[_fields.length];
-        for( int i=0; i<_fields.length; i++ )
-            flds[i] = _fields[i].dual();
-        return make(_name,flds);
-    }
-
-    // Keeps the same struct, but lower-bounds all fields.
-    @Override
-    public TypeStruct glb() {
-        if( _glb() ) return this;
-        // Need to glb each field
-        Field[] flds = new Field[_fields.length];
-        for( int i=0; i<_fields.length; i++ )
-            flds[i] = _fields[i].glb();
-        return make(_name,flds);
-    }
-    private boolean _glb() {
-        for( Field f : _fields )
-            if( f.glb() != f )
-                return false;
-        return true;
-    }
-
-    @Override
-    boolean eq(Type t) {
-        TypeStruct ts = (TypeStruct)t; // Invariant
-        if( !_name.equals(ts._name) )
-            return false;
-        if( _fields.length!=ts._fields.length )
-            return false;
-        for( int i = 0; i < _fields.length; i++ )
-            if( _fields[i] != ts._fields[i] )
-                return false;
-        return true;
-    }
-
-    @Override
-    int hash() {
-        long hash = _name.hashCode();
-        for( Field f : _fields ) hash = Utils.rot(hash,13) ^ f.hashCode();
-        return Utils.fold(hash);
-    }
-
-    @Override
-    public StringBuilder print(StringBuilder sb) {
-        if( this==BOT ) return sb.append("StructBot");
-        if( this==TOP ) return sb.append("StructTop");
-        sb.append(_name).append(" {\n");
-        for( Field f : _fields ) {
-            sb.append("  ").append(f._fname).append(":");
-            f._type.print(sb);
-            sb.append(";\n");
-        }
-        return sb.append("}");
-    }
-
-    @Override public String str() {
-        if( this==BOT ) return "StructBot";
-        if( this==TOP ) return "StructTop";
-        return _name;
-    }
-}
diff --git a/chapter10/src/main/java/com/seaofnodes/simple/type/TypeTuple.java b/chapter10/src/main/java/com/seaofnodes/simple/type/TypeTuple.java
deleted file mode 100644
index 0aa019a7..00000000
--- a/chapter10/src/main/java/com/seaofnodes/simple/type/TypeTuple.java
+++ /dev/null
@@ -1,88 +0,0 @@
-package com.seaofnodes.simple.type;
-
-import java.util.ArrayList;
-
-public class TypeTuple extends Type {
-
-    public final Type[] _types;
-
-    private TypeTuple(Type[] types) { super(TTUPLE); _types = types; }
-    public static TypeTuple make(Type... types) { return new TypeTuple(types).intern(); }
-
-    private static TypeTuple TEST = make(TypeInteger.BOT,TypeMemPtr.TEST);
-    public static void gather(ArrayList<Type> ts) {  ts.add(TEST); }
-
-    @Override
-    Type xmeet(Type other) {
-        TypeTuple tt = (TypeTuple)other;     // contract from xmeet
-        assert _types.length == tt._types.length;
-        Type[] ts = new Type[_types.length];
-        for( int i=0; i<_types.length; i++ )
-            ts[i] = _types[i].meet(tt._types[i]);
-        return make(ts);
-    }
-
-    @Override public Type dual() {
-        Type[] ts = new Type[_types.length];
-        for( int i=0; i<_types.length; i++ )
-            ts[i] = _types[i].dual();
-        return make(ts);
-    }
-
-    @Override
-    public Type glb() {
-        Type[] ts = new Type[_types.length];
-        for( int i=0; i<_types.length; i++ )
-            ts[i] = _types[i].glb();
-        return make(ts);
-    }
-
-    @Override
-    public StringBuilder print(StringBuilder sb) {
-        sb.append("[");
-        for( Type t : _types )
-            t.print(sb).append(",");
-        sb.setLength(sb.length()-1);
-        sb.append("]");
-        return sb;
-    }
-
-    @Override public String str() { return print(new StringBuilder()).toString(); }
-
-    /**
-     * Display Type name in a format that's good for IR printer
-     */
-    @Override
-    public StringBuilder typeName(StringBuilder sb) {
-        sb.append("[");
-        for( Type t : _types )
-            t.typeName(sb).append(",");
-        sb.setLength(sb.length()-1);
-        sb.append("]");
-        return sb;
-    }
-
-    public static final TypeTuple IF_BOTH    = make(new Type[]{Type. CONTROL,Type. CONTROL});
-    public static final TypeTuple IF_NEITHER = make(new Type[]{Type.XCONTROL,Type.XCONTROL});
-    public static final TypeTuple IF_TRUE    = make(new Type[]{Type. CONTROL,Type.XCONTROL});
-    public static final TypeTuple IF_FALSE   = make(new Type[]{Type.XCONTROL,Type. CONTROL});
-
-    @Override
-    int hash() {
-        int sum = 0;
-        for( Type type : _types ) sum ^= type.hashCode();
-        return sum;
-    }
-
-    @Override
-    boolean eq( Type t ) {
-        TypeTuple tt = (TypeTuple)t; // Contract
-        if( _types.length != tt._types.length ) return false;
-        for( int i=0; i<_types.length; i++ )
-            if( _types[i]!=tt._types[i] )
-                return false;
-        return true;
-    }
-
-
-}
diff --git a/chapter10/src/test/java/com/seaofnodes/simple/Chapter01Test.java b/chapter10/src/test/java/com/seaofnodes/simple/Chapter01Test.java
deleted file mode 100644
index 89882b2f..00000000
--- a/chapter10/src/test/java/com/seaofnodes/simple/Chapter01Test.java
+++ /dev/null
@@ -1,100 +0,0 @@
-package com.seaofnodes.simple;
-
-import com.seaofnodes.simple.node.*;
-import com.seaofnodes.simple.type.TypeInteger;
-import org.junit.Test;
-
-import static org.junit.Assert.*;
-
-public class Chapter01Test {
-
-    @Test
-    public void testSimpleProgram() {
-        Parser parser = new Parser("return 1;");
-        StopNode stop = parser.parse();
-        StartNode start = Parser.START;
-        ReturnNode ret = (ReturnNode)stop.in(0);
-
-        assertTrue(ret.ctrl() instanceof ProjNode);
-        Node expr = ret.expr();
-        if( expr instanceof ConstantNode con ) {
-            assertEquals(start,con.in(0));
-            assertEquals(TypeInteger.constant(1), con._type);
-        } else {
-            fail();
-        }
-    }
-
-    @Test
-    public void testZero() {
-        Parser parser = new Parser("return 0;");
-        parser.parse();
-        StartNode start = Parser.START;
-        for( Node use : start._outputs )
-            if( use instanceof ConstantNode con && con._type instanceof TypeInteger )
-                assertEquals(TypeInteger.constant(0),con._type);
-    }
-
-    @Test
-    public void testBad1() {
-        try {
-            new Parser("ret").parse();
-            fail();
-        } catch( RuntimeException e ) {
-            assertEquals("Undefined name 'ret'",e.getMessage());
-        }
-    }
-
-    @Test
-    public void testBad2() {
-        try {
-            new Parser("return 0123;").parse();
-            fail();
-        } catch( RuntimeException e ) {
-            assertEquals("Syntax error: integer values cannot start with '0'",e.getMessage());
-        }
-    }
-
-    @Test
-    public void testNotBad3() {
-        // this test used to fail in chapter 1
-        assertEquals("return 12;", new Parser("return --12;").parse().print());
-    }
-
-    @Test
-    public void testBad4() {
-        try {
-            new Parser("return 100").parse();
-            fail();
-        } catch( RuntimeException e ) {
-            assertEquals("Syntax error, expected ;: ",e.getMessage());
-        }
-    }
-
-    @Test
-    public void testNotBad5() {
-        // this test used to fail in chapter 1
-        assertEquals("return -100;", new Parser("return -100;").parse().print());
-    }
-
-    @Test
-    public void testBad6() {
-        try {
-            new Parser("return100").parse();
-            fail();
-        } catch( RuntimeException e ) {
-            assertEquals("Undefined name 'return100'",e.getMessage());
-        }
-    }
-
-    @Test
-    public void testBad7() {
-        try {
-            new Parser("return 1;}").parse();
-            fail();
-        } catch( RuntimeException e ) {
-            assertEquals("Syntax error, unexpected }",e.getMessage());
-        }
-    }
-
-}
diff --git a/chapter10/src/test/java/com/seaofnodes/simple/Chapter02Test.java b/chapter10/src/test/java/com/seaofnodes/simple/Chapter02Test.java
deleted file mode 100644
index a6075b75..00000000
--- a/chapter10/src/test/java/com/seaofnodes/simple/Chapter02Test.java
+++ /dev/null
@@ -1,60 +0,0 @@
-package com.seaofnodes.simple;
-
-import com.seaofnodes.simple.node.*;
-import com.seaofnodes.simple.type.TypeInteger;
-import org.junit.Test;
-
-import static org.junit.Assert.*;
-
-public class Chapter02Test {
-
-    @Test
-    public void testParseGrammar() {
-        Parser parser = new Parser("return 1+2*3+-5;");
-        StopNode ret = parser.parse();
-        assertEquals("return 2;", ret.print());
-    }
-
-    @Test
-    public void testAddPeephole() {
-        Parser parser = new Parser("return 1+2;");
-        StopNode ret = parser.parse();
-        assertEquals("return 3;", ret.print());
-    }
-
-    @Test
-    public void testSubPeephole() {
-        Parser parser = new Parser("return 1-2;");
-        StopNode ret = parser.parse();
-        assertEquals("return -1;", ret.print());
-    }
-
-    @Test
-    public void testMulPeephole() {
-        Parser parser = new Parser("return 2*3;");
-        StopNode ret = parser.parse();
-        assertEquals("return 6;", ret.print());
-    }
-
-    @Test
-    public void testDivPeephole() {
-        Parser parser = new Parser("return 6/3;");
-        StopNode ret = parser.parse();
-        assertEquals("return 2;", ret.print());
-    }
-
-    @Test
-    public void testMinusPeephole() {
-        Parser parser = new Parser("return 6/-3;");
-        StopNode ret = parser.parse();
-        assertEquals("return -2;", ret.print());
-    }
-
-    @Test
-    public void testExample() {
-        Parser parser = new Parser("return 1+2*3+-5;");
-        StopNode ret = parser.parse();
-        assertEquals("return 2;", ret.print());
-    }
-
-}
diff --git a/chapter10/src/test/java/com/seaofnodes/simple/Chapter03Test.java b/chapter10/src/test/java/com/seaofnodes/simple/Chapter03Test.java
deleted file mode 100644
index 609dff76..00000000
--- a/chapter10/src/test/java/com/seaofnodes/simple/Chapter03Test.java
+++ /dev/null
@@ -1,69 +0,0 @@
-package com.seaofnodes.simple;
-
-import com.seaofnodes.simple.node.*;
-import com.seaofnodes.simple.type.TypeInteger;
-import org.junit.Test;
-
-import static org.junit.Assert.*;
-
-public class Chapter03Test {
-
-    @Test
-    public void testVarDecl() {
-        Parser parser = new Parser("int a=1; return a;");
-        StopNode ret = parser.parse();
-        assertEquals("return 1;", ret.print());
-    }
-
-    @Test
-    public void testVarAdd() {
-        Parser parser = new Parser("int a=1; int b=2; return a+b;");
-        StopNode ret = parser.parse();
-        assertEquals("return 3;", ret.print());
-    }
-
-    @Test
-    public void testVarScope() {
-        Parser parser = new Parser("int a=1; int b=2; int c=0; { int b=3; c=a+b; } return c;");
-        StopNode ret = parser.parse();
-        assertEquals("return 4;", ret.print());
-    }
-
-    @Test
-    public void testVarDist() {
-        Parser parser = new Parser("int x0=1; int y0=2; int x1=3; int y1=4; return (x0-x1)*(x0-x1) + (y0-y1)*(y0-y1); ");
-        StopNode ret = parser.parse();
-        assertEquals("return 8;", ret.print());
-    }
-
-    @Test
-    public void testSelfAssign() {
-        try {
-            new Parser("int a=a; return a;").parse();
-            fail();
-        } catch( RuntimeException e ) {
-            assertEquals("Undefined name 'a'",e.getMessage());
-        }
-    }
-
-    @Test
-    public void testRedeclareVar() {
-        try {
-            new Parser("int a=1; int b=2; int c=0; int b=3; c=a+b;").parse();
-            fail();
-        } catch( RuntimeException e ) {
-            assertEquals("Redefining name 'b'",e.getMessage());
-        }
-    }
-
-    @Test
-    public void testBad1() {
-        try {
-            new Parser("int a=1; int b=2; int c=0; { int b=3; c=a+b;").parse();
-            fail();
-        } catch( RuntimeException e ) {
-            assertEquals("Syntax error, expected }: ",e.getMessage());
-        }
-    }
-
-}
diff --git a/chapter10/src/test/java/com/seaofnodes/simple/Chapter04Test.java b/chapter10/src/test/java/com/seaofnodes/simple/Chapter04Test.java
deleted file mode 100644
index f1603cc4..00000000
--- a/chapter10/src/test/java/com/seaofnodes/simple/Chapter04Test.java
+++ /dev/null
@@ -1,162 +0,0 @@
-package com.seaofnodes.simple;
-
-import com.seaofnodes.simple.node.*;
-import com.seaofnodes.simple.type.TypeInteger;
-import org.junit.Test;
-
-import static org.junit.Assert.*;
-
-public class Chapter04Test {
-
-    @Test
-    public void testPeephole() {
-        Parser parser = new Parser("return 1+arg+2; ");
-        StopNode ret = parser.parse();
-        assertEquals("return (arg+3);", ret.print());
-    }
-
-    @Test
-    public void testPeephole2() {
-        Parser parser = new Parser("return (1+arg)+2;");
-        StopNode ret = parser.parse();
-        assertEquals("return (arg+3);", ret.print());
-    }
-
-    @Test
-    public void testAdd0() {
-        Parser parser = new Parser("return 0+arg;");
-        StopNode ret = parser.parse();
-        assertEquals("return arg;", ret.print());
-    }
-
-    @Test
-    public void testAddAddMul() {
-        Parser parser = new Parser("return arg+0+arg;");
-        StopNode ret = parser.parse();
-        assertEquals("return (arg*2);", ret.print());
-    }
-
-    @Test
-    public void testPeephole3() {
-        Parser parser = new Parser("return 1+arg+2+arg+3; ");
-        StopNode ret = parser.parse();
-        assertEquals("return ((arg*2)+6);", ret.print());
-    }
-
-    @Test
-    public void testMul1() {
-        Parser parser = new Parser("return 1*arg;");
-        StopNode ret = parser.parse();
-        assertEquals("return arg;", ret.print());
-    }
-
-    @Test
-    public void testSub0() {
-        Parser parser = new Parser("return arg-0;");
-        StopNode ret = parser.parse();
-        assertEquals("return arg;", ret.print());
-    }
-
-    @Test
-    public void test0Sub() {
-        Parser parser = new Parser("return 0-arg;");
-        StopNode ret = parser.parse();
-        assertEquals("return (-arg);", ret.print());
-    }
-
-    @Test
-    public void testSubNeg() {
-        Parser parser = new Parser("return 3--arg;");
-        StopNode ret = parser.parse();
-        assertEquals("return (arg+3);", ret.print());
-    }
-
-    @Test
-    public void testNegSub() {
-        Parser parser = new Parser("return -arg-3;");
-        StopNode ret = parser.parse();
-        assertEquals("return (-(arg+3));", ret.print());
-    }
-
-    @Test
-    public void testVarArg() {
-        Parser parser = new Parser("return arg; ");
-        StopNode stop = parser.parse();
-        ReturnNode ret = stop.ret();
-        assertTrue(ret.in(0) instanceof ProjNode);
-        assertTrue(ret.in(1) instanceof ProjNode);
-    }
-
-    @Test
-    public void testConstantArg() {
-        Parser parser = new Parser("return arg; ", TypeInteger.constant(2));
-        StopNode ret = parser.parse();
-        assertEquals("return 2;", ret.print());
-    }
-
-    @Test
-    public void testCompEq() {
-        Parser parser = new Parser("return 3==3; ");
-        StopNode ret = parser.parse();
-        assertEquals("return 1;", ret.print());
-    }
-
-    @Test
-    public void testCompEq2() {
-        Parser parser = new Parser("return 3==4; ");
-        StopNode ret = parser.parse();
-        assertEquals("return 0;", ret.print());
-    }
-
-    @Test
-    public void testCompNEq() {
-        Parser parser = new Parser("return 3!=3; ");
-        StopNode ret = parser.parse();
-        assertEquals("return 0;", ret.print());
-    }
-
-    @Test
-    public void testCompNEq2() {
-        Parser parser = new Parser("return 3!=4; ");
-        StopNode ret = parser.parse();
-        assertEquals("return 1;", ret.print());
-    }
-
-    @Test
-    public void testBug1() {
-        Parser parser = new Parser("int a=arg+1; int b=a; b=1; return a+2; ");
-        StopNode ret = parser.parse();
-        assertEquals("return (arg+3);", ret.print());
-    }
-
-    @Test
-    public void testBug2() {
-        Parser parser = new Parser("int a=arg+1; a=a; return a; ");
-        StopNode ret = parser.parse();
-        assertEquals("return (arg+1);", ret.print());
-    }
-
-    @Test
-    public void testBug3() {
-        try {
-            new Parser("inta=1; return a;").parse();
-            fail();
-        } catch( RuntimeException e ) {
-            assertEquals("Undefined name 'inta'",e.getMessage());
-        }
-    }
-
-    @Test
-    public void testBug4() {
-        Parser parser = new Parser("return -arg;");
-        StopNode ret = parser.parse();
-        assertEquals("return (-arg);", ret.print());
-    }
-
-    @Test
-    public void testBug5() {
-        Parser parser = new Parser("return arg--2;");
-        StopNode ret = parser.parse();
-        assertEquals("return (arg--2);", ret.print());
-    }
-}
diff --git a/chapter10/src/test/java/com/seaofnodes/simple/Chapter05Test.java b/chapter10/src/test/java/com/seaofnodes/simple/Chapter05Test.java
deleted file mode 100644
index 35e54fa9..00000000
--- a/chapter10/src/test/java/com/seaofnodes/simple/Chapter05Test.java
+++ /dev/null
@@ -1,213 +0,0 @@
-package com.seaofnodes.simple;
-
-import com.seaofnodes.simple.node.*;
-import com.seaofnodes.simple.type.TypeInteger;
-import org.junit.Test;
-
-import static org.junit.Assert.*;
-
-public class Chapter05Test {
-
-    @Test
-    public void testIfStmt() {
-        Parser parser = new Parser(
-"""
-int a = 1;
-if (arg == 1)
-    a = arg+2;
-else {
-    a = arg-3;
-
-}
-
-return a;""");
-        StopNode ret = parser.parse().iterate();
-        assertEquals("return Phi(Region18,(arg+2),(arg-3));", ret.toString());
-    }
-
-    @Test
-    public void testTest() {
-        Parser parser = new Parser(
-"""
-int c = 3;
-int b = 2;
-if (arg == 1) {
-    b = 3;
-    c = 4;
-}
-return c;""", TypeInteger.BOT);
-        StopNode ret = parser.parse().iterate();
-        assertEquals("return Phi(Region16,4,3);", ret.toString());
-    }
-
-    @Test
-    public void testReturn2() {
-        Parser parser = new Parser(
-"""
-if( arg==1 )
-    return 3;
-else
-    return 4;
-""", TypeInteger.BOT);
-        StopNode stop = parser.parse();
-        assertEquals("Stop[ return 3; return 4; ]", stop.toString());
-    }
-
-    @Test
-    public void testIfMergeB() {
-        Parser parser = new Parser(
-"""
-int a=arg+1;
-int b=0;
-if( arg==1 )
-    b=a;
-else
-    b=a+1;
-return a+b;""");
-        StopNode ret = parser.parse().iterate();
-        assertEquals("return ((arg*2)+Phi(Region21,2,3));", ret.toString());
-    }
-
-    @Test
-    public void testIfMerge2() {
-        Parser parser = new Parser(
-"""
-int a=arg+1;
-int b=arg+2;
-if( arg==1 )
-    b=b+a;
-else
-    a=b+1;
-return a+b;""");
-        StopNode ret = parser.parse().iterate();
-        assertEquals("return ((Phi(Region32,(arg*2),arg)+arg)+Phi(Region,4,5));", ret.toString());
-    }
-
-    @Test
-    public void testMerge3() {
-        Parser parser = new Parser(
-"""
-int a=1;
-if( arg==1 )
-    if( arg==2 )
-        a=2;
-    else
-        a=3;
-else if( arg==3 )
-    a=4;
-else
-    a=5;
-return a;
-""", TypeInteger.BOT);
-        StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Region36,Phi(Region22,2,3),Phi(Region34,4,5));", stop.toString());
-    }
-
-    @Test
-    public void testMerge4() {
-        Parser parser = new Parser(
-"""
-int a=0;
-int b=0;
-if( arg )
-    a=1;
-if( arg==0 )
-    b=2;
-return arg+a+b;
-""", TypeInteger.BOT);
-        StopNode stop = parser.parse();
-        assertEquals("return ((arg+Phi(Region13,1,0))+Phi(Region28,2,0));", stop.toString());
-    }
-
-    @Test
-    public void testMerge5() {
-        Parser parser = new Parser(
-"""
-int a=arg==2;
-if( arg==1 )
-{
-    a=arg==3;
-}
-return a;""");
-        StopNode ret = parser.parse().iterate();
-        assertEquals("return (arg==Phi(Region16,3,2));", ret.toString());
-    }
-
-    @Test
-    public void testTrue() {
-      StopNode stop = new Parser("return true;").parse();
-      assertEquals("return 1;",stop.toString());
-    }
-
-    @Test
-    public void testHalfDef() {
-        try {
-            new Parser("if( arg==1 ) int b=2; return b;").parse();
-            fail();
-        } catch( RuntimeException e ) {
-            assertEquals("Cannot define a new name on one arm of an if",e.getMessage());
-        }
-    }
-
-    @Test
-    public void testHalfDef2() {
-        try {
-            new Parser("if( arg==1 ) { int b=2; } else { int b=3; } return b;").parse();
-            fail();
-        } catch( RuntimeException e ) {
-            assertEquals("Undefined name 'b'",e.getMessage());
-        }
-    }
-
-    @Test
-    public void testRegress1() {
-        try {
-            new Parser("if(arg==2) int a=1; else int b=2; return a;").parse();
-            fail();
-        } catch( RuntimeException e ) {
-            assertEquals("Cannot define a new name on one arm of an if",e.getMessage());
-        }
-    }
-
-
-    @Test
-    public void testBadNum() {
-        try {
-            new Parser("return 1-;").parse();
-            fail();
-        } catch( RuntimeException e ) {
-            assertEquals("Syntax error, expected an identifier or expression: ;",e.getMessage());
-        }
-    }
-
-    @Test
-    public void testKeyword1() {
-        try {
-            new Parser("int true=0; return true;").parse();
-            fail();
-        } catch( RuntimeException e ) {
-            assertEquals("Expected an identifier, found 'true'",e.getMessage());
-        }
-    }
-
-    @Test
-    public void testKeyword2() {
-        try {
-            new Parser("int else=arg; if(else) else=2; else else=1; return else;").parse();
-            fail();
-        } catch( RuntimeException e ) {
-            assertEquals("Expected an identifier, found 'else'",e.getMessage());
-        }
-    }
-
-    @Test
-    public void testKeyword3() {
-        try {
-            new Parser("int a=1; ififif(arg)inta=2;return a;").parse();
-            fail();
-        } catch( RuntimeException e ) {
-            assertEquals("Undefined name 'ififif'",e.getMessage());
-        }
-    }
-
-}
diff --git a/chapter10/src/test/java/com/seaofnodes/simple/Chapter06Test.java b/chapter10/src/test/java/com/seaofnodes/simple/Chapter06Test.java
deleted file mode 100644
index 097c2617..00000000
--- a/chapter10/src/test/java/com/seaofnodes/simple/Chapter06Test.java
+++ /dev/null
@@ -1,294 +0,0 @@
-package com.seaofnodes.simple;
-
-import com.seaofnodes.simple.node.*;
-import com.seaofnodes.simple.type.TypeInteger;
-import org.junit.Test;
-
-import static org.junit.Assert.*;
-
-public class Chapter06Test {
-
-    @Test
-    public void testPeepholeReturn() {
-        Parser parser = new Parser(
-"""
-if( true ) return 2;
-return 1;
-""");
-        StopNode stop = parser.parse().iterate();
-        assertEquals("return 2;", stop.toString());
-        assertTrue(stop.ret().ctrl() instanceof ProjNode);
-    }
-
-    @Test
-    public void testPeepholeRotate() {
-        Parser parser = new Parser(
-"""
-int a = 1;
-if (arg)
-    a = 2;
-return (arg < a) < 3;
-""");
-        StopNode stop = parser.parse().iterate();
-        assertEquals("return ((arg<Phi(Region12,2,1))<3);", stop.toString());
-    }
-
-    @Test
-    public void testPeepholeCFG() {
-        Parser parser = new Parser(
-"""
-int a=1;
-if( true )
-  a=2;
-else
-  a=3;
-return a;
-""");
-        StopNode stop = parser.parse().iterate();
-        assertEquals("return 2;", stop.toString());
-        assertTrue(stop.ret().ctrl() instanceof ProjNode);
-    }
-
-    @Test
-    public void testIfIf() {
-        Parser parser = new Parser(
-"""
-int a=1;
-if( arg!=1 )
-    a=2;
-else
-    a=3;
-int b=4;
-if( a==2 )
-    b=42;
-else
-    b=5;
-return b;""", TypeInteger.BOT);
-        StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Region37,42,5);", stop.toString());
-    }
-
-    @Test
-    public void testIfArgIf() {
-        Parser parser = new Parser(
-"""
-int a=1;
-if( 1==1 )
-    a=2;
-else
-    a=3;
-int b=4;
-if( arg==2 )
-    b=a;
-else
-    b=5;
-return b;""", TypeInteger.BOT);
-        StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Region30,2,5);", stop.toString());
-    }
-
-    @Test
-    public void testMerge3With2() {
-        Parser parser = new Parser(
-"""
-int a=1;
-if( arg==1 )
-    if( arg==2 )
-        a=2;
-    else
-        a=3;
-else if( arg==3 )
-    a=4;
-else
-    a=5;
-return a;
-""", TypeInteger.constant(2));
-        StopNode stop = parser.parse();
-        assertEquals("return 5;", stop.toString());
-    }
-
-    @Test
-    public void testMerge3With1() {
-        Parser parser = new Parser(
-"""
-int a=1;
-if( arg==1 )
-    if( arg==2 )
-        a=2;
-    else
-        a=3;
-else if( arg==3 )
-    a=4;
-else
-    a=5;
-return a;
-""", TypeInteger.constant(1));
-        StopNode stop = parser.parse().iterate();
-        assertEquals("return 3;", stop.toString());
-    }
-
-    @Test
-    public void testMerge3Peephole() {
-        Parser parser = new Parser(
-"""
-int a=1;
-if( arg==1 )
-    if( 1==2 )
-        a=2;
-    else
-        a=3;
-else if( arg==3 )
-    a=4;
-else
-    a=5;
-return a;
-""", TypeInteger.BOT);
-        StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Region41,3,Phi(Region39,4,5));", stop.toString());
-    }
-
-    @Test
-    public void testMerge3Peephole1() {
-        Parser parser = new Parser(
-"""
-int a=1;
-if( arg==1 )
-    if( 1==2 )
-        a=2;
-    else
-        a=3;
-else if( arg==3 )
-    a=4;
-else
-    a=5;
-return a;
-""", TypeInteger.constant(1));
-        StopNode stop = parser.parse().iterate();
-        assertEquals("return 3;", stop.toString());
-    }
-
-    @Test
-    public void testMerge3Peephole3() {
-        Parser parser = new Parser(
-"""
-int a=1;
-if( arg==1 )
-    if( 1==2 )
-        a=2;
-    else
-        a=3;
-else if( arg==3 )
-    a=4;
-else
-    a=5;
-return a;
-""", TypeInteger.constant(3));
-        StopNode stop = parser.parse().iterate();
-        assertEquals("return 4;", stop.toString());
-    }
-
-    @Test
-    public void testDemo1NonConst() {
-        Parser parser = new Parser("""
-int a = 0;
-int b = 1;
-if( arg ) {
-    a = 2;
-    if( arg ) { b = 2; }
-    else b = 3;
-}
-return a+b;
-""");
-        StopNode ret = parser.parse().iterate();
-        assertEquals("return Phi(Region24,4,1);", ret.toString());
-    }
-
-
-    @Test
-    public void testDemo1True() {
-        Parser parser = new Parser("""
-int a = 0;
-int b = 1;
-if( arg ) {
-    a = 2;
-    if( arg ) { b = 2; }
-    else b = 3;
-}
-return a+b;
-""", TypeInteger.constant(1));
-        StopNode ret = parser.parse().iterate();
-        assertEquals("return 4;", ret.toString());
-    }
-
-    @Test
-    public void testDemo1False() {
-        Parser parser = new Parser("""
-int a = 0;
-int b = 1;
-if( arg ) {
-    a = 2;
-    if( arg ) { b = 2; }
-    else b = 3;
-}
-return a+b;
-""", TypeInteger.constant(0));
-        StopNode ret = parser.parse().iterate();
-        assertEquals("return 1;", ret.toString());
-    }
-
-    @Test
-    public void testDemo2NonConst() {
-        Parser parser = new Parser("""
-int a = 0;
-int b = 1;
-int c = 0;
-if( arg ) {
-    a = 1;
-    if( arg==2 ) { c=2; } else { c=3; }
-    if( arg ) { b = 2; }
-    else b = 3;
-}
-return a+b+c;
-""");
-        StopNode ret = parser.parse().iterate();
-        assertEquals("return (Phi(Region36,Phi(Region23,2,3),0)+Phi(Region,3,1));", ret.toString());
-    }
-
-
-    @Test
-    public void testDemo2True() {
-        Parser parser = new Parser("""
-int a = 0;
-int b = 1;
-int c = 0;
-if( arg ) {
-    a = 1;
-    if( arg==2 ) { c=2; } else { c=3; }
-    if( arg ) { b = 2; }
-    else b = 3;
-}
-return a+b+c;
-""", TypeInteger.constant(1));
-        StopNode ret = parser.parse().iterate();
-        assertEquals("return 6;", ret.toString());
-    }
-
-    @Test
-    public void testDemo2arg2() {
-        Parser parser = new Parser("""
-int a = 0;
-int b = 1;
-int c = 0;
-if( arg ) {
-    a = 1;
-    if( arg==2 ) { c=2; } else { c=3; }
-    if( arg ) { b = 2; }
-    else b = 3;
-}
-return a+b+c;
-""", TypeInteger.constant(2));
-        StopNode ret = parser.parse().iterate();
-        assertEquals("return 5;", ret.toString());
-    }
-
-}
diff --git a/chapter10/src/test/java/com/seaofnodes/simple/Chapter07Test.java b/chapter10/src/test/java/com/seaofnodes/simple/Chapter07Test.java
deleted file mode 100644
index 58ecb7bc..00000000
--- a/chapter10/src/test/java/com/seaofnodes/simple/Chapter07Test.java
+++ /dev/null
@@ -1,222 +0,0 @@
-package com.seaofnodes.simple;
-
-import com.seaofnodes.simple.node.*;
-import com.seaofnodes.simple.type.TypeInteger;
-import org.junit.Test;
-
-import static org.junit.Assert.*;
-
-public class Chapter07Test {
-
-    @Test
-    public void testExample() {
-        Parser parser = new Parser(
-                """
-                while(arg < 10) {
-                    arg = arg + 1;
-                }
-                return arg;
-                """);
-        StopNode stop = parser.parse();
-        assertEquals("return Phi(Loop6,arg,(Phi_arg+1));", stop.toString());
-        assertTrue(stop.ret().ctrl() instanceof ProjNode);
-    }
-
-    @Test
-    public void testRegression() {
-        Parser parser = new Parser(
-"""
-int a = 1;
-if(arg){}else{
-    while(a < 10) {
-        a = a + 1;
-    }
-}
-return a;
-""");
-        StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Region24,1,Phi(Loop13,1,(Phi_a+1)));", stop.toString());
-    }
-
-    @Test
-    public void testWhileNested() {
-        Parser parser = new Parser(
-"""
-int sum = 0;
-int i = 0;
-while(i < arg) {
-    i = i + 1;
-    int j = 0;
-    while( j < arg ) {
-        sum = sum + j;
-        j = j + 1;
-    }
-}
-return sum;
-""");
-        StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Loop8,0,Phi(Loop20,Phi_sum,(Phi_sum+Phi(Loop,0,(Phi_j+1)))));", stop.toString());
-    }
-
-    @Test
-    public void testWhileScope() {
-        Parser parser = new Parser(
-"""
-int a = 1;
-int b = 2;
-while(a < 10) {
-    if (a == 2) a = 3;
-    else b = 4;
-}
-return b;
-""");
-        StopNode stop = parser.parse();
-        assertEquals("return Phi(Loop8,2,Phi(Region27,Phi_b,4));", stop.toString());
-        assertTrue(stop.ret().ctrl() instanceof ProjNode);
-    }
-
-    @Test
-    public void testWhileNestedIfAndInc() {
-        Parser parser = new Parser(
-"""
-int a = 1;
-int b = 2;
-while(a < 10) {
-    if (a == 2) a = 3;
-    else b = 4;
-    b = b + 1;
-    a = a + 1;
-}
-return b;
-""");
-        StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Loop8,2,(Phi(Region27,Phi_b,4)+1));", stop.toString());
-        assertTrue(stop.ret().ctrl() instanceof ProjNode);
-    }
-
-
-    @Test
-    public void testWhile() {
-        Parser parser = new Parser(
-"""
-int a = 1;
-while(a < 10) {
-    a = a + 1;
-    a = a + 2;
-}
-return a;
-""");
-        StopNode stop = parser.parse();
-        assertEquals("return Phi(Loop7,1,(Phi_a+3));", stop.toString());
-        assertTrue(stop.ret().ctrl() instanceof ProjNode);
-    }
-
-    @Test
-    public void testWhilePeep() {
-        Parser parser = new Parser(
-"""
-int a = 1;
-while(a < 10) {
-    a = a + 1;
-    a = a + 2;
-}
-return a;
-""");
-        StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Loop7,1,(Phi_a+3));", stop.toString());
-        assertTrue(stop.ret().ctrl() instanceof ProjNode);
-    }
-
-    @Test
-    public void testWhile2() {
-        Parser parser = new Parser(
-"""
-int a = 1;
-while(arg) a = 2;
-return a;
-""");
-        StopNode stop = parser.parse();
-        assertEquals("return Phi(Loop7,1,2);", stop.toString());
-        assertTrue(stop.ret().ctrl() instanceof ProjNode);
-    }
-
-    @Test
-    public void testWhile2Peep() {
-        Parser parser = new Parser(
-"""
-int a = 1;
-while(arg) a = 2;
-return a;
-""");
-        StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Loop7,1,2);", stop.toString());
-        assertTrue(stop.ret().ctrl() instanceof ProjNode);
-    }
-
-    @Test
-    public void testWhile3() {
-        Parser parser = new Parser(
-"""
-int a = 1;
-while(a < 10) {
-    int b = a + 1;
-    a = b + 2;
-}
-return a;
-""");
-        StopNode stop = parser.parse();
-        assertEquals("return Phi(Loop7,1,(Phi_a+3));", stop.toString());
-        assertTrue(stop.ret().ctrl() instanceof ProjNode);
-    }
-
-    @Test
-    public void testWhile3Peep() {
-        Parser parser = new Parser(
-"""
-int a = 1;
-while(a < 10) {
-    int b = a + 1;
-    a = b + 2;
-}
-return a;
-""");
-        StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Loop7,1,(Phi_a+3));", stop.toString());
-        assertTrue(stop.ret().ctrl() instanceof ProjNode);
-    }
-
-    @Test
-    public void testWhile4() {
-        Parser parser = new Parser(
-"""
-int a = 1;
-int b = 2;
-while(a < 10) {
-    int b = a + 1;
-    a = b + 2;
-}
-return a;
-""");
-        StopNode stop = parser.parse();
-        assertEquals("return Phi(Loop8,1,(Phi_a+3));", stop.toString());
-        assertTrue(stop.ret().ctrl() instanceof ProjNode);
-    }
-
-    @Test
-    public void testWhile4Peep() {
-        Parser parser = new Parser(
-"""
-int a = 1;
-int b = 2;
-while(a < 10) {
-    int b = a + 1;
-    a = b + 2;
-}
-return a;
-""");
-        StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Loop8,1,(Phi_a+3));", stop.toString());
-        assertTrue(stop.ret().ctrl() instanceof ProjNode);
-    }
-
-}
diff --git a/chapter10/src/test/java/com/seaofnodes/simple/Chapter08Test.java b/chapter10/src/test/java/com/seaofnodes/simple/Chapter08Test.java
deleted file mode 100644
index 6688d598..00000000
--- a/chapter10/src/test/java/com/seaofnodes/simple/Chapter08Test.java
+++ /dev/null
@@ -1,209 +0,0 @@
-package com.seaofnodes.simple;
-
-import com.seaofnodes.simple.evaluator.Evaluator;
-import com.seaofnodes.simple.node.*;
-import com.seaofnodes.simple.type.TypeInteger;
-import org.junit.Assert;
-import org.junit.Test;
-
-import static org.junit.Assert.*;
-
-public class Chapter08Test {
-
-    @Test
-    public void testEx6() {
-        Parser parser = new Parser(
-                """
-while(arg < 10) {
-    arg = arg + 1;
-    if (arg == 5)
-        break;
-    if (arg == 6)
-        break;
-}
-return arg;
-                """);
-        StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Region36,Phi(Region25,Phi(Loop6,arg,(Phi_arg+1)),Add),Add);", stop.toString());
-        assertTrue(stop.ret().ctrl() instanceof RegionNode);
-        Assert.assertEquals(5L, Evaluator.evaluate(stop, 1));
-        Assert.assertEquals(10L, Evaluator.evaluate(stop, 6));
-    }
-
-
-    @Test
-    public void testEx5() {
-        Parser parser = new Parser(
-                """
-int a = 1;
-while(arg < 10) {
-    arg = arg + 1;
-    if (arg == 5)
-        continue;
-    if (arg == 7)
-        continue;
-    a = a + 1;
-}
-return a;
-                """);
-        StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Loop7,1,Phi(Region42,Phi_a,(Phi_a+1)));", stop.toString());
-        assertTrue(stop.ret().ctrl() instanceof ProjNode);
-    }
-
-
-    @Test
-    public void testEx4() {
-        Parser parser = new Parser(
-                """
-while(arg < 10) {
-    arg = arg + 1;
-    if (arg == 5)
-        continue;
-    if (arg == 6)
-        break;
-}
-return arg;
-                """);
-        StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Region34,Phi(Loop6,arg,(Phi_arg+1)),Add);", stop.toString());
-        assertTrue(stop.ret().ctrl() instanceof RegionNode);
-    }
-
-    @Test
-    public void testEx3() {
-        Parser parser = new Parser(
-                """
-while(arg < 10) {
-    arg = arg + 1;
-    if (arg == 6)
-        break;
-}
-return arg;
-                """);
-        StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Region25,Phi(Loop6,arg,(Phi_arg+1)),Add);", stop.toString());
-        assertTrue(stop.ret().ctrl() instanceof RegionNode);
-    }
-
-
-    @Test
-    public void testEx2() {
-        Parser parser = new Parser(
-                """
-while(arg < 10) {
-    arg = arg + 1;
-    if (arg == 5)
-        continue;
-    if (arg == 6)
-        continue;
-}
-return arg;
-                """);
-        StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Loop6,arg,(Phi_arg+1));", stop.toString());
-        assertTrue(stop.ret().ctrl() instanceof ProjNode);
-    }
-
-
-    @Test
-    public void testEx1() {
-        Parser parser = new Parser(
-                """
-while(arg < 10) {
-    arg = arg + 1;
-    if (arg == 5)
-        continue;
-}
-return arg;
-                """);
-        StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Loop6,arg,(Phi_arg+1));", stop.toString());
-        assertTrue(stop.ret().ctrl() instanceof ProjNode);
-    }
-
-    @Test
-    public void testRegress1() {
-        Parser parser = new Parser(
-                """
-while( arg < 10 ) {
-    int a = arg+2;
-    if( a > 4 )
-        break;
-}
-return arg;
-                """);
-        StopNode stop = parser.parse().iterate();
-        assertEquals("return arg;", stop.toString());
-    }
-
-    @Test
-    public void testRegress2() {
-        Parser parser = new Parser("if(1) return 0;  else while(arg>--arg) arg=arg+1; return 0;");
-        StopNode stop = parser.parse().iterate();
-        assertEquals("return 0;", stop.toString());
-    }
-
-    @Test
-    public void testBreakOutsideLoop() {
-        try {
-            new Parser("""
-if(arg <= 10) {
-    break;
-    arg = arg + 1;
-}
-return arg;
-""").parse();
-            fail();
-        } catch( RuntimeException e ) {
-            assertEquals("No active loop for a break or continue",e.getMessage());
-        }
-    }
-
-    @Test
-    public void testRegress3() {
-        Parser parser = new Parser("""
-while(arg < 10) {
-    break;
-}
-return arg;
-""");
-        StopNode stop = parser.parse().iterate();
-        assertEquals("return arg;", stop.toString());
-    }
-
-    @Test
-    public void testRegress4() {
-        Parser parser = new Parser("""
-int a = 1;
-while(arg < 10) {
-    a = a + 1;
-    if (arg > 2) {
-        int a = 17;
-        break;
-    }
-}
-return a;
-""");
-        StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Region28,Phi(Loop7,1,(Phi_a+1)),Add);", stop.toString());
-        assertTrue(stop.ret().ctrl() instanceof RegionNode);
-    }
-
-    @Test
-    public void testRegress5() {
-        Parser parser = new Parser("""
-int a = 1;
-while(1) {
-    a = a + 1;
-    if (a<10) continue;
-    break;
-}
-return a;
-""");
-        StopNode stop = parser.parse().iterate();
-        assertEquals("return (Phi(Loop7,1,Add)+1);", stop.toString());
-        assertTrue(stop.ret().ctrl() instanceof ProjNode prj && prj._idx==1 );
-    }
-
-}
diff --git a/chapter10/src/test/java/com/seaofnodes/simple/Chapter09Test.java b/chapter10/src/test/java/com/seaofnodes/simple/Chapter09Test.java
deleted file mode 100644
index 048a58c7..00000000
--- a/chapter10/src/test/java/com/seaofnodes/simple/Chapter09Test.java
+++ /dev/null
@@ -1,301 +0,0 @@
-package com.seaofnodes.simple;
-
-import com.seaofnodes.simple.evaluator.Evaluator;
-import com.seaofnodes.simple.node.*;
-import com.seaofnodes.simple.type.Type;
-import com.seaofnodes.simple.type.TypeInteger;
-import org.junit.Assert;
-import org.junit.BeforeClass;
-import org.junit.Test;
-import org.junit.Ignore;
-
-import static org.junit.Assert.*;
-
-public class Chapter09Test {
-
-    @Test
-    @Ignore
-    public void testJig() {
-        Parser parser = new Parser("""
-int v0=0;
-arg=0;
-while(v0) {
-        while(1) if(arg*arg*0==0) {}
-                while(0) {}
-    arg=1;
-}
-return 0;
-                """);
-        StopNode stop = parser.parse().iterate();
-    }
-
-    @Test
-    public void testGVN1() {
-        Parser parser = new Parser(
-                """
-int x = arg + arg;
-if(arg < 10) {
-    return arg + arg;
-}
-else {
-    x = x + 1;
-}
-return x;
-                """);
-        StopNode stop = parser.parse();
-        assertEquals("Stop[ return (arg*2); return (Mul+1); ]", stop.toString());
-        Assert.assertEquals(2L, Evaluator.evaluate(stop, 1));
-        Assert.assertEquals(23L, Evaluator.evaluate(stop, 11));
-    }
-
-    @Test
-    public void testGVN2() {
-        Parser parser = new Parser(
-                """
-return arg*arg-arg*arg;
-                """);
-        StopNode stop = parser.parse();
-        assertEquals("return 0;", stop.toString());
-        Assert.assertEquals(0L, Evaluator.evaluate(stop, 1));
-    }
-
-    @Test
-    public void testWorklist1() {
-        Parser parser = new Parser(
-                """
-int step = 1;
-while (arg < 10) {
-    arg = arg + step + 1;
-}
-return arg;
-                """);
-        StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Loop7,arg,(Phi_arg+2));", stop.toString());
-        Assert.assertEquals(11L, Evaluator.evaluate(stop, 1));
-    }
-
-    @Test
-    public void testWorklist2() {
-        Parser parser = new Parser(
-                """
-int cond = 0;
-int one = 1;
-while (arg < 10) {
-    if (cond) one = 2;
-    arg = arg + one*3 + 1;
-}
-return arg;
-                """);
-        StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Loop8,arg,(Phi_arg+4));", stop.toString());
-        Assert.assertEquals(13L, Evaluator.evaluate(stop, 1));
-    }
-
-    @Test
-    public void testWorklist3() {
-        Parser parser = new Parser(
-                """
-int v1 = 0;
-int v2 = 0;
-int v3 = 0;
-int v4 = 0;
-int v5 = 0;
-int v6 = 0;
-int v7 = 0;
-int v8 = 0;
-while (arg) {
-    if (v1) v2 = 1;
-    if (v2) v3 = 1;
-    if (v3) v4 = 1;
-    if (v4) v5 = 1;
-    if (v5) v6 = 1;
-    if (v6) v7 = 1;
-    if (v7) v8 = 1;
-    arg = arg + v8 + 1;
-}
-return arg;
-                """);
-        StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Loop14,arg,(Phi_arg+1));", stop.toString());
-    }
-
-    @Test
-    public void testRegionPeepBug() {
-        Parser parser = new Parser(
-                """
-int v0=0;
-int v1=0;
-while(v1+arg) {
-    arg=0;
-    int v2=v0;
-    while(arg+1) {}
-    v0=1;
-    v1=v2;
-}
-                """);
-        StopNode stop = parser.parse().iterate();
-        assertEquals("Stop[ ]", stop.toString());
-    }
-
-    @Test
-    public void testWhile0() {
-        Parser parser = new Parser("while(0) continue; if(0) arg=0;");
-        StopNode stop = parser.parse().iterate();
-        assertEquals("Stop[ ]", stop.toString());
-    }
-
-    @Test
-    public void testWhile1() {
-        Parser parser = new Parser("""
-if(0) while(0) {
-    int arg=arg;
-    while(0) {}
-}
-""");
-        StopNode stop = parser.parse().iterate();
-        assertEquals("Stop[ ]", stop.toString());
-    }
-
-
-    @Test
-    public void testPrecedence() {
-        Parser parser = new Parser("return 3-1+2;");
-        StopNode stop = parser.parse().iterate();
-        assertEquals("return 4;", stop.toString());
-    }
-
-    @Test
-    public void testSwap2() {
-        Parser parser = new Parser("return 1+(1+1);");
-        StopNode stop = parser.parse().iterate();
-        assertEquals("return 3;", stop.toString());
-    }
-
-
-    @Test
-    public void testFuzz0() {
-        Parser parser = new Parser("""
-int one = 1;
-int a = 0;
-int zero = 0;
-while(arg) {
-    a = -(one + a + 2);
-    arg = arg + 1;
-    one = one + zero;
-}
-return a;
-""");
-        StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Loop9,0,(-(Phi_a+3)));", stop.toString());
-    }
-
-    @Test
-    public void testFuzz1() {
-        Parser parser = new Parser("""
-while(1) {}
-while(arg) break;
-while(arg) arg=0;
-arg=0;
-int v0=0!=0<-0;
-return -0+0+0;
-""");
-        StopNode stop = parser.parse().iterate();
-        assertEquals("Stop[ ]", stop.toString());
-    }
-
-
-    @Test
-    public void testFuzz2() {
-        Parser parser = new Parser("return 0+-0;");
-        StopNode stop = parser.parse().iterate();
-        assertEquals("return 0;", stop.toString());
-    }
-
-    @Test
-    public void testFuzz3() {
-        Parser parser = new Parser("int v0=0; while(0==69) while(v0) return 0;");
-        StopNode stop = parser.parse().iterate();
-        assertEquals("Stop[ ]", stop.toString());
-    }
-
-    @Test
-    public void testFuzz4() {
-        Parser parser = new Parser("""
-while(1) {
-    arg=0<=0;
-    if(1<0) while(arg==-0) arg=arg-arg;
-}
-""");
-        StopNode stop = parser.parse().iterate();
-        assertEquals("Stop[ ]", stop.toString());
-    }
-
-    @Test
-    public void testFuzz5() {
-        Parser parser = new Parser("""
-{
-    int v0=0;
-    while(1)
-            int v1=0--0;
-    while(v0)
-        break;
-    while(-v0) {
-        while(0+0+v0) continue;
-        break;
-    }
-    if(-0!=-0+0+v0) while(0+0+0+0)
-                break;
-}
-return 0!=0;
-""");
-        StopNode stop = parser.parse().iterate();
-        assertEquals("Stop[ ]", stop.toString());
-    }
-
-    @Test
-    public void testFuzz6() {
-        Parser parser = new Parser("""
-int v0=0;
-while(0==1) while(v0)
-        v0=1+v0;
-                                   """);
-        StopNode stop = parser.parse().iterate();
-        assertEquals("Stop[ ]", stop.toString());
-    }
-
-    @Test
-    public void testFuzz7() {
-        Parser parser = new Parser("""
-while(1) {}
-int v0=0;
-while(v0)
-    {}
-int v1=0;
-while(1)
-        v1=1;
-return v1+v0;
-                                   """);
-        StopNode stop = parser.parse().iterate();
-        assertEquals("Stop[ ]", stop.toString());
-    }
-
-    @Test
-    public void testFuzz8() {
-        Parser parser = new Parser("while(arg) arg = arg - 1;  return arg;");
-        StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Loop6,arg,(Phi_arg-1));", stop.toString());
-    }
-
-    @Test
-    public void testMeet() {
-        Type t1 = Type.TOP;
-        Type t2 = TypeInteger.TOP;
-        Assert.assertEquals(TypeInteger.TOP, t1.meet(t2));
-        Assert.assertEquals(TypeInteger.TOP, t2.meet(t1));
-        t1 = Type.BOTTOM;
-        t2 = TypeInteger.BOT;
-        Assert.assertEquals(Type.BOTTOM, t1.meet(t2));
-        Assert.assertEquals(Type.BOTTOM, t2.meet(t1));
-    }
-
-}
diff --git a/chapter10/src/test/java/com/seaofnodes/simple/Chapter10Test.java b/chapter10/src/test/java/com/seaofnodes/simple/Chapter10Test.java
deleted file mode 100644
index da9a4c5f..00000000
--- a/chapter10/src/test/java/com/seaofnodes/simple/Chapter10Test.java
+++ /dev/null
@@ -1,461 +0,0 @@
-package com.seaofnodes.simple;
-
-import com.seaofnodes.simple.node.Node;
-import com.seaofnodes.simple.node.StopNode;
-import com.seaofnodes.simple.type.*;
-import org.junit.Test;
-
-import java.util.Arrays;
-
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.fail;
-
-public class Chapter10Test {
-    @Test public void testDeadReferenceReturn() {
-        for( String body : new String[] {
-            "return new S; return 0;",
-            "if(1) return new S; else return 0;"
-        } ) {
-            String src = "struct S { int x; }; " + body;
-            var stop = new Parser(src).parse().iterate();
-            org.junit.Assert.assertTrue(body,
-                stop.ret().expr()._type instanceof com.seaofnodes.simple.type.TypeMemPtr);
-        }
-    }
-
-
-
-    // Issue #246: null-check guards start in Chapter 10; arrays arrive in Chapter 15.
-    private static final String NULLABLE_POINT_SOURCE = """
-        struct Point { int x; };
-        Point point = new Point;
-        point.x = 42;
-        Point? p = null;
-        if (arg) p = point;
-        """;
-
-    @Test
-    public void testNullGuards() {
-        for( String body : new String[] {
-            "if (p != null) return p.x; return -1;",
-            "if (null != p) return p.x; return -1;",
-            "if (!!!!p) return p.x; return -1;",
-            "if (!!!p) return -1; else return p.x;",
-            "int b = !!p; if (b) return p.x + b - 1; return -1;"
-        } ) {
-            StopNode stop = new Parser(NULLABLE_POINT_SOURCE+body).parse().iterate();
-            assertEquals(body,-1L,com.seaofnodes.simple.evaluator.Evaluator.evaluate(stop,0));
-            assertEquals(body,42L,com.seaofnodes.simple.evaluator.Evaluator.evaluate(stop,1));
-        }
-    }
-
-    @Test
-    public void testNullGuardErrors() {
-        for( String body : new String[] {
-            "return p.x;",
-            "if (p == null) return p.x; return -1;",
-            "if (!!point) return p.x; return -1;",
-            "if (!!p) { int x = p.x; } return p.x;"
-        } ) {
-            try {
-                new Parser(NULLABLE_POINT_SOURCE+body).parse().iterate();
-                fail(body);
-            } catch( RuntimeException e ) {
-                // Known null is rejected during parsing in these chapters.
-                String expected = body.startsWith("if (p == null)")
-                    ? "Accessing unknown field 'x' from 'null'" : "Might be null accessing 'x'";
-                assertEquals(body,expected,e.getMessage());
-            }
-        }
-    }
-
-    @Test
-    public void testFuzzer() {
-        Parser parser = new Parser(
-"""
-int a = arg/3;
-int b = arg*5;
-int x = arg*7;
-int y = arg/11;
-int p; int g; int h;
-if( (arg/13)==0 ) {
-    p = x + y;
-    g = x;
-    h = y;
-} else {
-    p = a + b;
-    g = a;
-    h = b;
-}
-int r = g+h;
-return p-r;
-""");
-        StopNode stop = parser.parse().iterate();
-        assertEquals("return 0;", stop.toString());
-    }
-
-    @Test
-    public void testStruct() {
-        Parser parser = new Parser("""
-struct Bar {
-    int a;
-    int b;
-}
-struct Foo {
-    int x;
-}
-Foo? foo = null;
-Bar bar = new Bar;
-bar.a = 1;
-bar.a = 2;
-return bar.a;
-""");
-        StopNode stop = parser.parse().iterate();
-        assertEquals("return 2;", stop.toString());
-    }
-
-    @Test
-    public void testExample() {
-        Parser parser = new Parser("""
-struct Vector2D { int x; int y; }
-Vector2D v = new Vector2D;
-v.x = 1;
-if (arg)
-    v.y = 2;
-else
-    v.y = 3;
-return v;
-""");
-        StopNode stop = parser.parse().iterate();
-        assertEquals("return new Vector2D;", stop.toString());
-    }
-
-    @Test
-    public void testBug() {
-        Parser parser = new Parser("""
-struct s0 {
-    int v0;
-}
-s0? v1=null;
-int v3=v1.zAicm;
-""");
-        try { parser.parse();  fail(); }
-        catch( Exception e ) {  assertEquals("Accessing unknown field 'zAicm' from 'null'",e.getMessage());  }
-    }
-
-    @Test
-    public void testBug2() {
-        Parser parser = new Parser("""
-struct s0 { int v0; }
-arg=0+new s0.0;
-""");
-        try { parser.parse(); fail(); }
-        catch( Exception e ) { assertEquals("Expected an identifier, found 'null'",e.getMessage()); }
-    }
-
-    @Test
-    public void testLoop() {
-        Parser parser = new Parser("""
-struct Bar { int a; }
-Bar bar = new Bar;
-while (arg) {
-    bar.a = bar.a + 2;
-    arg = arg + 1;
-}
-return bar.a;
-""");
-        StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Loop10,0,(Phi_a+2));", stop.toString());
-    }
-
-    @Test
-    public void testIf() {
-        Parser parser = new Parser("""
-struct Bar { int a; }
-Bar bar = new Bar;
-if (arg) bar = null;
-bar.a = 1;
-return bar.a;
-""");
-        try { parser.parse().iterate(); fail(); }
-        catch( Exception e ) { assertEquals("Type null is not of declared type *Bar",e.getMessage()); }
-    }
-
-    @Test
-    public void testIf2() {
-        Parser parser = new Parser("""
-struct Bar { int a; }
-Bar? bar = null;
-if (arg) bar = new Bar;
-bar.a = 1;
-return bar.a;
-""");
-        try { parser.parse().iterate(); fail(); }
-        catch( Exception e ) { assertEquals("Might be null accessing 'a'",e.getMessage()); }
-    }
-
-    @Test
-    public void testIf3() {
-        Parser parser = new Parser("""
-struct Bar { int a; }
-Bar bar = null;
-if (arg) bar = null;
-bar.a = 1;
-return bar.a;
-""");
-        try { parser.parse(); fail(); }
-        catch( Exception e ) { assertEquals("Type null is not of declared type *Bar", e.getMessage()); }
-    }
-
-    @Test
-    public void testIfOrNull() {
-        Parser parser = new Parser("""
-struct Bar { int a; }
-Bar? bar = new Bar;
-if (arg) bar = null;
-if( bar ) bar.a = 1;
-return bar;
-""");
-        StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Region15,null,new Bar);", stop.toString());
-    }
-
-    @Test
-    public void testIfOrNull2() {
-        Parser parser = new Parser(
-"""
-struct Bar { int a; }
-Bar? bar = new Bar;
-if (arg) bar = null;
-int rez = 3;
-if( !bar ) rez=4;
-else bar.a = 1;
-return rez;
-""");
-        StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Region32,4,3);", stop.toString());
-    }
-
-    @Test
-    public void testWhileWithNullInside() {
-        Parser parser = new Parser("""
-struct s0 {int v0;}
-s0? v0 = new s0;
-int ret = 0;
-while(arg) {
-    ret = v0.v0;
-    v0 = null;
-    arg = arg - 1;
-}
-return ret;
-""");
-        try { parser.parse().iterate(); fail(); }
-        catch( Exception e ) { assertEquals("Might be null accessing 'v0'", e.getMessage()); }
-    }
-
-    @Test
-    public void testRedeclareStruct() {
-        Parser parser = new Parser("""
-struct s0 {
-    int v0;
-}
-s0? v1=new s0;
-s0? v1;
-v1=new s0;
-""");
-        try { parser.parse(); fail(); }
-        catch( Exception e ) { assertEquals("Redefining name 'v1'", e.getMessage()); }
-    }
-
-    @Test
-    public void testIter() {
-        // Build and use an iterator
-        Parser parser = new Parser(
-"""
-struct Iter {
-    int x;
-    int len;
-}
-Iter i = new Iter;
-i.len = arg;
-int sum=0;
-while( i.x < i.len ) {
-    sum = sum + i.x;
-    i.x = i.x + 1;
-}
-return sum;
-""");
-        StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Loop14,0,(Phi(Loop,0,(Phi_x+1))+Phi_sum));", stop.toString());
-    }
-
-
-
-
-    @Test
-    public void test1() {
-        Parser parser = new Parser("""
-struct s0 {int v0;}
-s0 ret = new s0;
-while(arg) {
-    s0 v0 = new s0;
-    v0.v0 = arg;
-    arg = arg-1;
-    if (arg==5) ret=v0;
-}
-return ret;
-""");
-        StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Loop10,new s0,Phi(Region31,new s0,Phi_ret));", stop.toString());
-    }
-
-    @Test
-    public void test2() {
-        Parser parser = new Parser("""
-struct s0 {int v0;}
-s0 ret = new s0;
-s0 v0 = new s0;
-while(arg) {
-    v0.v0 = arg;
-    arg = arg-1;
-    if (arg==5) ret=v0;
-}
-return ret;
-""");
-        StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Loop13,new s0,Phi(Region32,new s0,Phi_ret));", stop.toString());
-    }
-
-
-    @Test
-    public void test3() {
-        Parser parser = new Parser("""
-struct s0 {int v0;}
-s0 ret = new s0;
-while(arg < 10) {
-    s0 v0 = new s0;
-    if (arg == 5) ret=v0;
-    arg = arg + 1;
-}
-return ret;
-""");
-        StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Loop10,new s0,Phi(Region30,new s0,Phi_ret));", stop.toString());
-    }
-
-    @Test
-    public void testBug3() {
-        Parser parser = new Parser("""
-struct s0 {
-    int f0;
-}
-if(0>=0) return new s0;
-return new s0;
-int v0=null.f0;
-""");
-        try { parser.parse(); fail(); }
-        catch( Exception e ) { assertEquals("Accessing unknown field 'f0' from 'null'", e.getMessage()); }
-    }
-
-    @Test
-    public void testBug4() {
-        Parser parser = new Parser("""
-if(0) {
-    while(0) if(arg) continue;
-    int v0=0;
-    while(1) {
-        int arg=-arg;
-        v0=arg;
-    }
-}
-   """);
-        StopNode stop = parser.parse().iterate();
-        assertEquals("Stop[ ]", stop.toString());
-    }
-
-    @Test
-    public void testBug5() {
-        Parser parser = new Parser("""
-struct s0 {
-    int f0;
-}
-if(0) return 0;
-else return new s0;
-if(new s0.f0) return 0;
-    """);
-        StopNode stop = parser.parse().iterate();
-        assertEquals("return new s0;", stop.toString());
-    }
-
-    @Test
-    public void testBug6MissedWorklist() {
-        Parser parser = new Parser("""
-while(0) {}
-int v4=0;
-while(0<arg) {
-    v4=v4+1;
-    while(1) v4=-v4;
-    while(0) arg=-1;
-}
-return 0;
-    """);
-        StopNode stop = parser.parse().iterate();
-    }
-
-    @Test
-    public void testBug7() {
-        Parser parser = new Parser("""
-struct s0 {  int f0; }
-s0 v0 = new s0;
-while(v0.f0) {}
-s0 v1 = v0;
-return v1;
-    """);
-        StopNode stop = parser.parse().iterate();
-        assertEquals("return new s0;", stop.toString());
-    }
-
-
-    @Test
-    public void testBug8() {
-        Parser parser = new Parser("""
-int v2=0;
-while(0)
-while(0) {}
-{
-    {
-        {
-            int v36=0;
-            {
-                while(0) {
-                    {
-                        while(-v2) {
-                            {
-                                while(v36) {
-                                                while(v2) return 0;
-                                                break;
-                                }                            }
-                            if(-v2) break;
-                        }
-                    }
-                }
-            }
-        }    }
-}
-""");
-        StopNode stop = parser.parse().iterate();
-        assertEquals("Stop[ ]", stop.toString());
-    }
-
-    @Test
-    public void testBug9() {
-        Parser parser = new Parser("""
-int v0=arg==0;
-while(v0) continue;
-return 0;
-""");
-        StopNode stop = parser.parse().iterate();
-        assertEquals("return 0;", stop.toString());
-    }
-
-}
diff --git a/chapter10/src/test/java/com/seaofnodes/simple/FuzzerWrap.java b/chapter10/src/test/java/com/seaofnodes/simple/FuzzerWrap.java
deleted file mode 100644
index 019140ad..00000000
--- a/chapter10/src/test/java/com/seaofnodes/simple/FuzzerWrap.java
+++ /dev/null
@@ -1,50 +0,0 @@
-package com.seaofnodes.simple;
-
-import com.seaofnodes.simple.fuzzer.Fuzzer;
-import org.junit.Test;
-import org.junit.Ignore;
-
-
-import static org.junit.Assert.assertTrue;
-
-/**
- * Normal tests run chapter-local regression seeds. Open failures and exploratory
- * fuzzing are opt-in (run directly in the IDE or temporarily remove Ignore).
- * Seeds depend on this chapter's generator; do not copy them between chapters.
- */
-public class FuzzerWrap {
-
-    private static final long[] REGRESSION_SEEDS = {
-    };
-
-    private static final long[] OPEN_FAILING_SEEDS = {
-    };
-
-    @Test         public void fuzzPeepsRegression  () { fuzzPeepsSeeds(REGRESSION_SEEDS); }
-    @Test @Ignore public void fuzzPeepsOpenFailures() { fuzzPeepsSeeds(OPEN_FAILING_SEEDS); }
-
-    private static void fuzzPeepsSeeds(long... seeds) {
-        var fuzzer = new Fuzzer();
-        for (long seed : seeds)
-            fuzzer.fuzzPeepsRegression(seed);
-    }
-
-    @Test
-    @Ignore
-    public void fuzzPeepsLarge() {
-        var fuzzer = new Fuzzer();
-        for (int i=0; i<1000000; i++)
-            fuzzer.fuzzPeeps(i);
-        assertTrue(fuzzer.noExceptions());
-    }
-
-
-    @Test
-    @Ignore
-    public void fuzzPeepTiming() {
-        var fuzzer = new Fuzzer();
-        int max_nid=0;
-        for (int i=0; i<1000000; i++)
-            max_nid = fuzzer.fuzzPeepTiming(i, max_nid);
-    }
-}
diff --git a/chapter10/src/test/java/com/seaofnodes/simple/SchedulerTest.java b/chapter10/src/test/java/com/seaofnodes/simple/SchedulerTest.java
deleted file mode 100644
index ad595822..00000000
--- a/chapter10/src/test/java/com/seaofnodes/simple/SchedulerTest.java
+++ /dev/null
@@ -1,73 +0,0 @@
-package com.seaofnodes.simple;
-
-import com.seaofnodes.simple.evaluator.Evaluator;
-import com.seaofnodes.simple.node.StopNode;
-import org.junit.Assert;
-import org.junit.Ignore;
-import org.junit.Test;
-
-import static org.junit.Assert.assertEquals;
-
-public class SchedulerTest {
-
-    private static void assertObj(Object obj, String name, Object... fields) {
-        assertEquals(Evaluator.Obj.class, obj.getClass());
-        var o = (Evaluator.Obj)obj;
-        assertEquals(name, o.struct()._name);
-        Assert.assertArrayEquals(fields, o.fields());
-    }
-
-    @Test
-    @Ignore
-    public void testJig() {
-        Parser parser = new Parser("""
-struct S {
-    int f;
-}
-S v=new S;
-v.f = 2;
-int i=v.f;
-if (arg) v.f=1;
-return i;
-""");
-        StopNode stop = parser.parse();//.iterate();
-        var eval = new Evaluator(stop);
-        assertEquals(2L, eval.evaluate(1, 10));
-    }
-
-    @Test
-    public void testStoreInIf() {
-        Parser parser = new Parser("""
-struct S {
-    int f;
-}
-S v0=new S;
-if(arg) v0.f=1;
-return v0;
-""");
-        StopNode stop = parser.parse().iterate();
-        var eval = new Evaluator(stop);
-        assertObj(eval.evaluate(0, 10), "S", 0L);
-        assertObj(eval.evaluate(1, 10), "S", 1L);
-    }
-
-    @Test
-    public void testStoreInIf2() {
-        Parser parser = new Parser("""
-struct S {
-    int f;
-}
-S v=new S;
-v.f = 2;
-int i=new S.f;
-i=v.f;
-if (arg) v.f=1;
-return i;
-""");
-        StopNode stop = parser.parse().iterate();
-        var eval = new Evaluator(stop);
-        assertEquals(2L, eval.evaluate(0, 10));
-        assertEquals(2L, eval.evaluate(1, 10));
-    }
-
-}
diff --git a/chapter10/src/test/java/com/seaofnodes/simple/TypeTest.java b/chapter10/src/test/java/com/seaofnodes/simple/TypeTest.java
deleted file mode 100644
index f9c580cc..00000000
--- a/chapter10/src/test/java/com/seaofnodes/simple/TypeTest.java
+++ /dev/null
@@ -1,145 +0,0 @@
-package com.seaofnodes.simple;
-
-import com.seaofnodes.simple.type.*;
-import org.junit.Assert;
-import org.junit.Test;
-
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertSame;
-
-public class TypeTest {
-
-    // Test basic properties and GLB
-    @Test
-    public void testTypeAdHoc() {
-        TypeStruct s1 = TypeStruct.make("s1", new Field[]{
-                Field.make("a", TypeInteger.BOT),
-                Field.make("b", TypeInteger.BOT) });
-        TypeStruct s2 = TypeStruct.make("s2", new Field[]{
-                Field.make("a", TypeInteger.BOT),
-                Field.make("b", TypeInteger.BOT) });
-        Assert.assertEquals(s1, s1.glb());
-        Assert.assertNotEquals(s1, s1.dual());
-        Assert.assertEquals(s1, s1.dual().glb());
-
-        TypeMem m1 = TypeMem.make(1);
-        TypeMem m2 = TypeMem.make(2);
-        TypeMem m3 = TypeMem.make(3);
-        TypeMem m4 = TypeMem.make(4);
-
-        Assert.assertNotEquals(m1, m2);
-        Assert.assertNotEquals(m2, m3);
-        Assert.assertNotEquals(m3, m4);
-
-        Assert.assertEquals(TypeStruct.BOT, s1.meet(s2));
-        Assert.assertEquals(TypeMem   .BOT, m1.meet(m2));
-        Assert.assertEquals(TypeMem   .BOT, m2.meet(m3));
-        Assert.assertEquals(TypeMem   .BOT, m3.meet(m4));
-
-        Assert.assertEquals(TypeMem.BOT, m1.glb());
-        Assert.assertEquals(m1, m1.dual());
-        Assert.assertEquals(TypeMem.TOP, m1.glb().dual());
-
-        TypeMemPtr ptr1 = TypeMemPtr.make(s1);
-        Assert.assertEquals(s1, ptr1._obj);
-        TypeMemPtr ptr2 = TypeMemPtr.make(s2);
-        Assert.assertEquals(s2, ptr2._obj);
-
-        TypeMemPtr ptr1nil = TypeMemPtr.make(s1, true);
-        Assert.assertEquals(s1, ptr1nil._obj);
-        Assert.assertTrue(ptr1nil._nil);
-        Assert.assertFalse(ptr1nil._obj==null);
-        TypeMemPtr ptr2nil = TypeMemPtr.make(s2, true);
-        Assert.assertEquals(s2, ptr2nil._obj);
-
-        Assert.assertNotEquals(ptr1, ptr2);
-        Assert.assertNotEquals(ptr1, ptr1.glb());
-        Assert.assertEquals(ptr1nil, ptr1.glb());
-
-        Assert.assertEquals(ptr1, ptr1.dual().dual());
-        Assert.assertEquals(ptr1.glb(), ptr1.dual().glb());
-        Assert.assertEquals(TypeMemPtr.BOT, ptr1.meet(ptr2nil));
-        Assert.assertEquals(ptr1.glb(), ptr1.meet(TypeMemPtr.NULLPTR));
-
-        TypeMemPtr TOP = TypeMemPtr.TOP;
-        TypeMemPtr BOT = TypeMemPtr.BOT;
-        TypeMemPtr PTR = TypeMemPtr.VOIDPTR;
-        TypeMemPtr NULL = TypeMemPtr.NULLPTR;
-        Type PTR_meet_NULL = NULL.meet(PTR);
-        Assert.assertEquals(BOT, PTR_meet_NULL);
-        Type ptr1_meet_ptr2 = ptr1.meet(ptr2);
-        Assert.assertEquals(PTR, ptr1_meet_ptr2);
-        Type NULL_join_ptr1 = NULL.join(ptr1);
-        Assert.assertEquals(TOP, NULL_join_ptr1);
-        Type NULL_join_PTR = PTR.join(NULL);
-        Assert.assertEquals(TOP, NULL_join_PTR);
-        Type ptr1_dual = ptr1.dual();
-        Type nullableptr1_dual = ptr1nil.dual();
-    }
-
-    // Test theoretical properties.
-    // This is a symmetric complete bounded (ranked) lattice.
-    // Also the meet is commutative and associative.
-    // The lattice has a dual (symmetric), and join is ~(~x meet ~y).
-    // See https://en.wikipedia.org/wiki/Lattice_(order).
-    @Test
-    public void testLatticeTheory() {
-        Type[] ts = Type.gather();
-
-        // Confirm commutative & complete
-        for( Type t0 : ts )
-            for( Type t1 : ts ) {
-                check_commute  (t0,t1);
-                check_symmetric(t0,t1);
-            }
-
-        // Confirm associative
-        for( Type t0 : ts )
-            for( Type t1 : ts )
-                for( Type t2 : ts )
-                    assoc(t0,t1,t2);
-
-        // Confirm symmetry.  If A isa B, then A.join(C) isa B.join(C)
-        for( Type t0 : ts )
-            for( Type t1 : ts )
-                if( t0.isa(t1) )
-                    for( Type t2 : ts ) {
-                        Type t02 = t0.join(t2);
-                        Type t12 = t1.join(t2);
-                        Type mt  = t02.meet(t12);
-                        assertSame(mt,t12);
-                    }
-    }
-
-    // By design in meet, args are already flipped to order _type, which forces
-    // symmetry for things with badly ordered _type fields.  The question is
-    // still interesting for other orders.
-    private static void check_commute( Type t0, Type t1 ) {
-        if( t0==t1 ) return;
-        if( t0.is_simple() && !t1.is_simple() ) return; // By design, flipped the only allowed order
-        Type mta = t0.meet(t1);
-        Type mtb = t1.meet(t0); // Reverse args and try again
-        assertSame(mta,mtb);
-    }
-
-    // A & B = MT
-    // Expect: ~A & ~MT == ~A
-    // Expect: ~B & ~MT == ~B
-    private static void check_symmetric( Type t0, Type t1 ) {
-        if( t1==t0 ) return;
-        Type mt = t0.meet(t1);
-        Type ta = mt.dual().meet(t1.dual());
-        Type tb = mt.dual().meet(t0.dual());
-        assertSame(ta,t1.dual());
-        assertSame(tb,t0.dual());
-    }
-
-    private static void assoc( Type t0, Type t1, Type t2 ) {
-        Type t01   = t0 .meet(t1 );
-        Type t12   = t1 .meet(t2 );
-        Type t01_2 = t01.meet(t2 );
-        Type t0_12 = t0 .meet(t12);
-        assertSame(t01_2,t0_12);
-    }
-
-}
diff --git a/chapter10/src/test/java/com/seaofnodes/simple/evaluator/Evaluator.java b/chapter10/src/test/java/com/seaofnodes/simple/evaluator/Evaluator.java
deleted file mode 100644
index 3cf5c57b..00000000
--- a/chapter10/src/test/java/com/seaofnodes/simple/evaluator/Evaluator.java
+++ /dev/null
@@ -1,209 +0,0 @@
-package com.seaofnodes.simple.evaluator;
-
-import com.seaofnodes.simple.Utils;
-import com.seaofnodes.simple.node.*;
-import com.seaofnodes.simple.type.Field;
-import com.seaofnodes.simple.type.TypeInteger;
-import com.seaofnodes.simple.type.TypeMemPtr;
-import com.seaofnodes.simple.type.TypeStruct;
-
-import java.lang.invoke.MethodHandle;
-import java.lang.invoke.MethodHandles;
-import java.util.ArrayList;
-import java.util.BitSet;
-import java.util.Objects;
-
-public class Evaluator {
-
-    private static final Object MEMORY = new Object();
-
-    public record Obj(TypeStruct struct, Object[] fields) {
-        @Override
-        public String toString() {
-            var sb = new StringBuilder();
-            sb.append("Obj<").append(struct._name).append("> {");
-            for(int i=0; i<struct._fields.length; i++) {
-                sb.append("\n  ").append(struct._fields[i]._fname).append("=").append(fields[i]);
-            }
-            return sb.append("\n}").toString();
-        }
-    }
-
-    private static int getFieldIndex(TypeStruct struct, MemOpNode memop) {
-        int idx = struct.find(memop._name);
-        if( idx >= 0 ) return idx;
-        throw new AssertionError("Field "+memop._name+" not found in struct " + struct._name);
-    }
-
-    public enum Status {
-        TIMEOUT,
-        FALLTHROUGH
-    }
-
-    /**
-     * Find the start node from some node in the graph or null if there is no start node
-     */
-    private static StartNode findStart(BitSet visit, Node node) {
-        if (node == null) return null;
-        if( visit.get(node._nid) ) return null;
-        visit.set(node._nid);
-        StartNode start = node instanceof StartNode ? (StartNode) node : null;
-        for( Node def : node._inputs ) {
-            var res = findStart(visit,def);
-            if( res != null ) start = res;
-        }
-        for( Node use : node._outputs ) {
-            var res = findStart(visit,use);
-            if( res != null ) start = res;
-        }
-        return start;
-    }
-
-    private final Object[] values;
-    private final ArrayList<Object> phiCache = new ArrayList<>();
-    private final StartNode start;
-    private final Scheduler.Block startBlock;
-
-    public Evaluator(Node graph) {
-        var visited = new BitSet();
-        this.start = findStart(visited, graph);
-        if (this.start == null) {
-            this.values = null;
-            this.startBlock = null;
-            return;
-        }
-        this.startBlock = Scheduler.schedule(this.start);
-        this.values = new Object[visited.length()];
-    }
-
-    private long div(DivNode div) {
-        long in2 = vall(div.in(2));
-        return in2 == 0 ? 0 : vall(div.in(1)) / in2;
-    }
-
-    private Object alloc(NewNode alloc) {
-        var type = ((TypeMemPtr)alloc.compute())._obj;
-        return new Obj(type, new Object[type._fields.length]);
-    }
-
-    private Object load(LoadNode load) {
-        var from = (Obj)val(load.in(2));
-        var idx = getFieldIndex(from.struct, load);
-        return from.fields[idx];
-    }
-
-    private Object store(StoreNode store) {
-        var to = (Obj)val(store.in(2));
-        var val = val(store.in(3));
-        var idx = getFieldIndex(to.struct, store);
-        to.fields[idx] = val;
-        return null;
-    }
-
-    private static boolean isTrue(Object obj) {
-        if (obj == null) return false;
-        if (obj instanceof Number n) return n.longValue() != 0;
-        return true;
-    }
-
-    private Object val(Node node) {
-        return values[node._nid];
-    }
-
-    private long vall(Node node) {
-        var v = val(node);
-        if (v instanceof Number n) return n.longValue();
-        throw new AssertionError("Not a long " + v);
-    }
-
-    private Object cons(ConstantNode cons) {
-        var type = cons.compute();
-        if (type instanceof TypeInteger i) return i.value();
-        assert type instanceof TypeMemPtr;
-        return null;
-    }
-
-    private Object exec(Node node) {
-        return switch (node) {
-            case ConstantNode cons  -> cons(cons);
-            case AddNode      add   -> vall(add.in(1)) + vall(add.in(2));
-            case BoolNode.EQ  eq    -> Objects.equals(val(eq.in(1)), val(eq.in(2))) ? 1L : 0L;
-            case BoolNode.LE  le    -> vall(le.in(1)) <= vall(le.in(2)) ? 1L : 0L;
-            case BoolNode.LT  lt    -> vall(lt.in(1)) <  vall(lt.in(2)) ? 1L : 0L;
-            case DivNode      div   -> div(div);
-            case MinusNode    minus -> -vall(minus.in(1));
-            case MulNode      mul   -> vall(mul.in(1)) * vall(mul.in(2));
-            case NotNode      not   -> isTrue(val(not.in(1))) ? 0L : 1L;
-            case SubNode      sub   -> vall(sub.in(1)) - vall(sub.in(2));
-            case CastNode     cast  -> val(cast.in(1));
-            case LoadNode     load  -> load(load);
-            case StoreNode    store -> store(store);
-            case NewNode      alloc -> alloc(alloc);
-            case ProjNode     proj  -> ((Object[])val(proj.ctrl()))[proj._idx];
-            default                 -> throw new AssertionError("Unexpected node " + node);
-        };
-    }
-
-    /**
-     * Run the graph until either a return is found or the number of loop iterations are done.
-     */
-    public Object evaluate(long parameter, int loops) {
-        if (start == null) return Status.TIMEOUT;
-        var s = new Object[start.compute()._types.length];
-        s[1] = parameter;
-        for(int i=2;i<s.length;i++) s[i] = MEMORY;
-        values[start._nid] = s;
-        int i=0;
-        Scheduler.Block block = this.startBlock;
-        for(;;) {
-            for(; i<block.nodes().length;i++) values[block.nodes()[i]._nid] = exec(block.nodes()[i]);
-            i=0;
-            switch (block.exit()) {
-                case null:
-                    return Status.FALLTHROUGH;
-                case ReturnNode ret:
-                    return val(ret.in(1));
-                case IfNode ifn:
-                    block = block.next()[isTrue(val(ifn.in(1))) ? 0 : 1];
-                    if (block == null) return Status.FALLTHROUGH;
-                    break;
-                case RegionNode region:
-                    if (loops-- <= 0) return Status.TIMEOUT;
-                    int exit = block.exitId();
-                    assert exit > 0 && region.nIns() > exit;
-                    block = block.next()[0];
-                    assert block != null;
-                    for (; i < block.nodes().length; i++) {
-                        if (!(block.nodes()[i] instanceof PhiNode)) break;
-                        phiCache.add(val(block.nodes()[i].in(exit)));
-                    }
-                    for (i=0; i<phiCache.size(); i++) {
-                        values[block.nodes()[i]._nid] = phiCache.get(i);
-                    }
-                    phiCache.clear();
-                    break;
-                default:
-                    throw Utils.TODO("Unexpected control node " + block.exit());
-            }
-        }
-    }
-
-    public static Object evaluate(StopNode graph) {
-        return evaluate(graph, 0);
-    }
-
-    public static Object evaluate(StopNode graph, long parameter) {
-        return evaluate(graph, parameter, 1000);
-    }
-
-    public static Object evaluate(StopNode graph, long parameter, int loops) {
-        var res = evaluateWithResult(graph, parameter, loops);
-        if (res == Status.TIMEOUT) throw new RuntimeException("Timeout");
-        return res;
-    }
-
-    public static Object evaluateWithResult(StopNode graph, long parameter, int loops) {
-        return new Evaluator(graph).evaluate(parameter, loops);
-    }
-
-}
diff --git a/chapter10/src/test/java/com/seaofnodes/simple/evaluator/Scheduler.java b/chapter10/src/test/java/com/seaofnodes/simple/evaluator/Scheduler.java
deleted file mode 100644
index 674d12f5..00000000
--- a/chapter10/src/test/java/com/seaofnodes/simple/evaluator/Scheduler.java
+++ /dev/null
@@ -1,592 +0,0 @@
-package com.seaofnodes.simple.evaluator;
-
-import com.seaofnodes.simple.Utils;
-import com.seaofnodes.simple.node.*;
-import com.seaofnodes.simple.type.Type;
-
-import java.util.*;
-
-/**
- * A late scheduler for test cases.
- * <br>
- * <br>
- * This scheduler is used for tests and is not the final scheduler.
- * <br>
- * <br>
- * The scheduler schedules not as late as possible. Since it is just for test cases this is fine.
- * A better scheduler will try to place nodes outside of loops. Due to the schedule late strategy
- * this scheduler might place initialization code in loops.
- * <br>
- * We schedule late here since memory edges have some implicit information. There can only be one
- * memory edge (for a field) at a time. However, before <code>if</code> statements this might split.
- * When scheduling early a store might be moved out of the loop but then there are two edges alive.
- * The one through the store node and the adjacent one. This is an invalid schedule and instead of
- * handling this case a late scheduler does not have this problem as memory edges are combined
- * through phi nodes.
- * <br>
- * <br>
- * A bit about this scheduler. It first discovers all alive nodes and allocates side data for them.
- * Then the control flow graph is build. Then, all phis are placed and finally all the remaining nodes
- * in an order where a node is placed when all alive uses are placed. Finally, the output is produced.
- */
-public class Scheduler {
-
-    /**
-     * A basic block with a schedule of the containing nodes.
-     *
-     * @param nodes The nodes in the final schedule of this block
-     * @param exit The exit node of this block.
-     * @param exitId In case the next block is a region this gives the entry id into the region.
-     * @param next The next blocks.
-     */
-    public record Block(Node[] nodes, Node exit, int exitId, Block[] next) {}
-
-    /**
-     * Definition of a block in the building process.
-     */
-    private static class BasicBlock {
-
-        /**
-         * Dominator of this block
-         */
-        final BasicBlock dom;
-        /**
-         * Id of this block where <code>a.depth < b.depth</code> means that a is before b or
-         * both are in different branches.
-         */
-        final int depth;
-        /**
-         * Previous blocks
-         */
-        final BasicBlock[] prev;
-        /**
-         * Entry to this block
-         */
-        final Node entry;
-        /**
-         * Schedules node in reverse order.
-         */
-        final ArrayList<Node> reverseSchedule = new ArrayList<>();
-
-        /**
-         * Initialize the block.
-         * @param entry The node that started this block
-         * @param depth The depth of this node. All previous nodes need to have a lower value.
-         * @param prev The previous blocks.
-         */
-        BasicBlock(Node entry, int depth, BasicBlock... prev) {
-            BasicBlock dom = null;
-            int max = -1;
-            for(var bb: prev) {
-                max = Math.max(max, bb.depth);
-                dom = dom==null?bb:dom(dom, bb);
-            }
-            assert depth > max;
-            this.dom = dom;
-            this.depth = depth;
-            this.entry = entry;
-            this.prev = prev;
-        }
-
-    }
-
-    /**
-     * Ancillary data for nodes used during the scheduling process.
-     */
-    private static class NodeData {
-
-        /**
-         * The node this ancillary data is used for.
-         */
-        final Node node;
-
-        /**
-         * Number of alive users not yet scheduled.
-         */
-        int users = 1;
-
-        /**
-         * Block into which the node should be placed so far.
-         * This will be updated with every placed use.
-         */
-        BasicBlock block;
-
-        /**
-         * Initialize ancillary data for a node
-         * @param node The node this ancillary data is associated with.
-         */
-        NodeData(Node node) {
-            this.node = node;
-        }
-
-    }
-
-    /**
-     * Ancillary data for nodes.
-     */
-    private final IdentityHashMap<Node, NodeData> data = new IdentityHashMap<>();
-    /**
-     * List of nodes which can be placed since all users are placed.
-     */
-    private final Stack<NodeData> scheduleQueue = new Stack<>();
-
-    /**
-     * Get the ancillary data for an alive node.
-     * @param node The node for which the ancillary data is requested.
-     * @return The ancillary data for the node.
-     */
-    NodeData d(Node node) {
-        return od(node).orElseThrow(AssertionError::new);
-    }
-
-    /**
-     * Get the ancillary data for a potentially dead node.
-     * @param node The node for which the ancillary data is requested.
-     * @return The ancillary data for the node an alive node or
-     * <code>Optional.empty()</code> for <code>null</code> or dead nodes.
-     */
-    Optional<NodeData> od(Node node) {
-        return Optional.ofNullable(data.get(node));
-    }
-
-    /**
-     * Checks a node for validity
-     * @param data The node to check.
-     * @return true if all placed inputs are before this node.
-     */
-    private boolean isValid(NodeData data) {
-        return data.node._inputs.stream().map(i->i==null?null:d(i)).map(d->d==null||d.users>0?null:d.block).allMatch(d->d==null||dom(d, data.block)==d);
-    }
-
-    /**
-     * Checks that node is not XCtrl.
-     * @param node The node to check.
-     * @return true if the node is not XCtrl.
-     */
-    private static boolean isNotXCtrl(Node node) {
-        return !(node instanceof ConstantNode c && c.compute() == Type.XCONTROL);
-    }
-
-    /**
-     * Return the dominator of <code>a</code> and <code>b</code>
-     * @param a Block a
-     * @param b Block b
-     * @return The dominator of <code>a</code> and <code>b</code>
-     */
-    private static BasicBlock dom(BasicBlock a, BasicBlock b) {
-        while (a!=b) {
-            if (a.depth >= b.depth) a=a.dom;
-            if (b.depth > a.depth) b=b.dom;
-        }
-        return a;
-    }
-
-    /**
-     * Return if a is before b.
-     * @param a Block a
-     * @param b Block b
-     * @return true is a is before b.
-     */
-    private static boolean isBefore(BasicBlock a, BasicBlock b) {
-        while (b.depth > a.depth) {
-            while (b.dom.depth > a.depth) b = b.dom;
-            for (int i=0; i<b.prev.length-1; i++) {
-                if (isBefore(a, b.prev[i])) return true;
-            }
-            b = b.prev[b.prev.length-1];
-        }
-        return a == b;
-    }
-
-    /**
-     * Is node placed during the control flow graph build.
-     * @param data Node to check.
-     * @return true if node is placed during the control flow graph build.
-     */
-    private static boolean isPinnedNode(NodeData data) {
-        return data.node.isCFG() || data.node instanceof PhiNode;
-    }
-
-    /**
-     * Refine placement of a node.
-     * @param data The node to refine.
-     * @param block The block before the node should be scheduled.
-     */
-    private void refinePlacement(NodeData data, BasicBlock block) {
-        assert !isPinnedNode(data);
-        data.block = data.block == null ? block : dom(data.block, block);
-        assert isValid(data);
-    }
-
-    /**
-     * Refine placement if before is happening before data
-     * @param data The node for which the placement should be refined.
-     * @param before The node before which the data node should be placed.
-     */
-    private void optionalRefinePlacement(NodeData data, Node before) {
-        od(before).ifPresent(d->{
-            // before might be in a different branch. So check this case with isBefore
-            // and only refine the placement if it is not in a different branch.
-            if (isBefore(d.block, data.block)) refinePlacement(data, d.block);
-        });
-    }
-
-    /**
-     * Schedule all nodes not yet scheduled.
-     */
-    private void doSchedule() {
-        while (!scheduleQueue.isEmpty()) {
-            var data = scheduleQueue.pop();
-            assert !isPinnedNode(data);
-
-            assert data.block != null;
-            assert data.users == 0;
-
-            if (data.node instanceof LoadNode l) {
-                assert isValid(data);
-                // Handle anti-deps of load nodes.
-                // At this point all anti-dep nodes are scheduled,
-                // but they did not refine the placement
-                // so do that now.
-                var mem = l.in(1);
-                for(var out : mem._outputs) {
-                    if (out instanceof PhiNode p) {
-                        var r = p.in(0);
-                        for (int i = 1; i < p.nIns(); i++) {
-                            if (p.in(i) == mem) optionalRefinePlacement(data, r.in(i));
-                        }
-                    } else if (!(out instanceof LoadNode)) {
-                        optionalRefinePlacement(data, out);
-                    }
-                }
-            }
-
-            assert isValid(data);
-            data.block.reverseSchedule.add(data.node);
-
-            for(var in:data.node._inputs) {
-                if (in!=null) update(d(in), data.block);
-            }
-            if (data.node instanceof StoreNode s) {
-                // Store nodes have anti-deps to load nodes.
-                // So decrease the uses of these loads when the store is placed.
-                for (var out: s.in(1)._outputs) {
-                    if (out instanceof LoadNode) od(out).ifPresent(this::decUsers);
-                }
-            }
-        }
-
-        // Now all nodes should be placed and have a block assigned
-        assert this.data.values().stream().noneMatch(d->d.block==null);
-    }
-
-    /**
-     * Decrement the not-yet-placed users of a block.
-     * @param data The node for which the users should be decremented.
-     */
-    private void decUsers(NodeData data) {
-        assert data.users > 0;
-        if (--data.users == 0) {
-            assert data.block != null;
-            assert isValid(data);
-
-            // When all users are gone this node can be scheduled.
-            scheduleQueue.push(data);
-        }
-    }
-
-    /**
-     * Update the placement of a node
-     * @param data The node to update
-     * @param block The block before which the node should happen.
-     */
-    private void update(NodeData data, BasicBlock block) {
-        assert block != null;
-        if (data.users == 0) {
-            assert isPinnedNode(data);
-            return;
-        }
-        refinePlacement(data, block);
-        decUsers(data);
-    }
-
-    /**
-     * Checks if a CFG node is ready to be placed. This is used for regions joining branches.
-     * @param node The CFG node to check
-     * @return true if all parents of a CFG node are placed.
-     */
-    private boolean isCFGNodeReady(Node node) {
-        if (node instanceof LoopNode l) {
-            assert d(l.in(1)).block != null;
-        } else if (node instanceof RegionNode r) {
-            for(int i=1; i<r.nIns(); i++) {
-                if (od(r.in(i)).map(d->d.block==null).orElse(false)) return false;
-            }
-        } else {
-            assert d(node.in(0)).block != null;
-        }
-        return true;
-    }
-
-    /**
-     * Schedule all phi nodes.
-     * @param phiQueue List of all the phi nodes to schedule.
-     */
-    private void schedulePhis(Stack<NodeData> phiQueue) {
-        while(!phiQueue.empty()) {
-            var data = phiQueue.pop();
-            var phi = (PhiNode) data.node;
-            var r = phi.in(0);
-            data.block = d(r).block;
-            for(int i=1; i<phi.nIns(); i++) {
-                var in = phi.in(i);
-                od(r.in(i)).ifPresent(d->update(d(in), d.block));
-            }
-        }
-    }
-
-    /**
-     * Build the control flow graph.
-     * @param start The start node.
-     */
-    private void doBuildCTF(StartNode start) {
-        var queue = new Stack<NodeData>();
-        var phiQueue = new Stack<NodeData>();
-        queue.push(d(start));
-        int depth = 0;
-        while (!queue.isEmpty()) {
-            var data = queue.pop();
-            var node = data.node;
-            assert node.isCFG();
-            BasicBlock block;
-            switch (node) {
-                case StartNode s:
-                    block = new BasicBlock(s, depth++);
-                    break;
-                case LoopNode l:
-                    block = new BasicBlock(l, depth++, d(l.in(1)).block);
-                    break;
-                case RegionNode r:
-                    var prev = new ArrayList<BasicBlock>();
-                    for(int i=1; i<r.nIns(); i++) {
-                        od(r.in(i)).ifPresent(d->prev.add(d.block));
-                    }
-                    block = new BasicBlock(r, depth++, prev.toArray(BasicBlock[]::new));
-                    break;
-                case IfNode i:
-                    block = d(i.in(0)).block;
-                    break;
-                case ReturnNode r:
-                    block = d(r.in(0)).block;
-                    break;
-                default:
-                    block = new BasicBlock(node, depth++, d(node.in(0)).block);
-            }
-            data.block = block;
-            if (node instanceof RegionNode r) {
-                // Regions might have phis which need to be scheduled.
-                // Put them on a list for later scheduling.
-                for (var out:r._outputs) {
-                    if (out instanceof PhiNode p) {
-                        var d = this.data.get(p);
-                        if (d!=null) {
-                            d.users=0;
-                            phiQueue.push(d);
-                        }
-                    }
-                }
-            }
-            if (!(node instanceof ReturnNode))
-                for (Node n:node._outputs) if (n.isCFG() && isCFGNodeReady(n) && d(n).block == null) queue.push(d(n));
-            var b = block;
-            for(var in:data.node._inputs) od(in).ifPresent(d->update(d, b));
-        }
-
-        // Schedule all phi nodes.
-        schedulePhis(phiQueue);
-    }
-
-    /**
-     * Mark a node alive and create ancillary data for it.
-     * @param queue List into which this node should be placed if it needs to be visited.
-     * @param node Node which should be marked alive.
-     * @param cfg If this node is a CFG node.
-     */
-    private void markAlive(Stack<NodeData> queue, Node node, boolean cfg) {
-        var nd = od(node).orElse(null);
-        if (nd != null) {
-            // Node was already visited, just increase the users.
-            if (nd.users>0) nd.users++;
-            return;
-        }
-        assert node.isCFG() == cfg;
-        assert isNotXCtrl(node);
-        nd = new NodeData(node);
-        if (cfg) nd.users=0;
-        data.put(node, nd);
-        queue.push(nd);
-    }
-
-    /**
-     * Mark all alive nodes.
-     * First all CFG nodes are marked, then all other nodes.
-     * @param node THe start node.
-     */
-    private void doMarkAlive(Node node) {
-        var cfgQueue = new Stack<NodeData>();
-        var dataQueue = new Stack<NodeData>();
-        var mem = new Stack<NodeData>();
-        markAlive(cfgQueue, node, true);
-        // Mark all CFG nodes.
-        while (!cfgQueue.isEmpty()) {
-            var data = cfgQueue.pop();
-            node = data.node;
-            assert node.isCFG();
-            if (!(node instanceof ReturnNode)) {
-                for (var out : node._outputs) if (out.isCFG() && isNotXCtrl(out)) markAlive(cfgQueue, out, true);
-            }
-            for (var in : node._inputs) if(in!=null && !in.isCFG() && isNotXCtrl(in)) markAlive(dataQueue, in, false);
-        }
-        // Mark all other nodes.
-        while (!dataQueue.isEmpty()) {
-            var data = dataQueue.pop();
-            node = data.node;
-            assert !node.isCFG();
-            if (node instanceof PhiNode phi) {
-                var r = phi.in(0);
-                for (int i=1; i<phi.nIns(); i++) {
-                    if (od(r.in(i)).isPresent()) markAlive(dataQueue, phi.in(i), false);
-                }
-            } else {
-                for (var in : node._inputs) if (in != null && !in.isCFG()) markAlive(dataQueue, in, false);
-            }
-            if (node instanceof StoreNode) mem.push(data);
-        }
-        // Handle store nodes and increase load with an anti-dep to the store.
-        while (!mem.isEmpty()) {
-            var data = mem.pop();
-            node = data.node;
-            for(var out:node.in(1)._outputs) {
-                if (out instanceof LoadNode) od(out).ifPresent(d->d.users++);
-            }
-        }
-    }
-
-    /**
-     * Helper function to append the nodes of a block to an array of nodes
-     * @param arr The array the nodes of a block should be appended to.
-     * @param node A potentially separator node
-     * @param block The block from which the nodes should be appended.
-     * @return The combined new array.
-     */
-    private static Node[] appendNodes(Node[] arr, Node node, BasicBlock block) {
-        var idx = arr.length;
-        arr = Arrays.copyOf(arr, arr.length+block.reverseSchedule.size()+(node==null?0:1));
-        if (node != null) arr[idx++] = node;
-        for(int i=block.reverseSchedule.size()-1;i>=0;i--) {
-            arr[idx++] = block.reverseSchedule.get(i);
-        }
-        return arr;
-    }
-
-    /**
-     * Find the CFG output of a node
-     * @param node The node
-     * @return THe CFG output of the node.
-     */
-    private static Node findSingleCFGOut(Node node) {
-        if (node instanceof StartNode) {
-            for(var n:node._outputs) if (n instanceof ProjNode p && p._idx==0) return p;
-            return null;
-        }
-        assert node._outputs.stream().filter(Node::isCFG).limit(2).count()<=1;
-        for(var n:node._outputs) if(n.isCFG()) return n;
-        return null;
-    }
-
-    /**
-     * Build the final data structure after all the scheduling happened.
-     * @param start The start node
-     * @return The final schedule.
-     */
-    private Block build(Node start) {
-        var blocks = new IdentityHashMap<Node, Block>();
-        var queue = new Stack<NodeData>();
-        queue.push(d(start));
-
-        // Visit all CFG nodes and create blocks for them.
-        // This can combine blocks.
-        while(!queue.isEmpty()) {
-            var data = queue.pop();
-            var first = data.node;
-            Node prev;
-            var last = first;
-            Node[] arr = new Node[0];
-            if (first instanceof RegionNode) {
-                var nodes = new ArrayList<Node>();
-                for(var out: first._outputs) {
-                    if (out instanceof PhiNode) {
-                        if(od(out).isPresent()) nodes.add(out);
-                    }
-                }
-                arr = nodes.toArray(arr);
-            }
-            arr = appendNodes(arr, null, data.block);
-            assert !(first instanceof IfNode);
-            for(;;) {
-                prev = last;
-                last = findSingleCFGOut(last);
-                if (last == null) break;
-                if (last instanceof RegionNode) {
-                    if (blocks.get(last) == null && last != first)
-                        queue.push(d(last));
-                    break;
-                }
-                if (last instanceof ReturnNode) break;
-                if (last instanceof IfNode if_) {
-                    for(var out:if_._outputs) if (out.isCFG() && blocks.get(out) == null) queue.push(d(out));
-                    break;
-                }
-                data = d(last);
-                arr = appendNodes(arr, data.node, data.block);
-            }
-            blocks.put(first, switch(last) {
-                case null -> new Block(arr, null, -1, new Block[0]);
-                case IfNode i -> new Block(arr, i, -1, new Block[2]);
-                case RegionNode r -> new Block(arr, r, Utils.find(r._inputs, prev), new Block[1]);
-                case ReturnNode r -> new Block(arr, r, -1, new Block[0]);
-                default -> throw new AssertionError("Unexpected block exit node");
-            });
-        }
-        // Update the next pointer of all blocks.
-        for (var block: blocks.values()) {
-            switch(block.exit) {
-                case null: break;
-                case IfNode i:
-                    for(var out:i._outputs) if (out instanceof ProjNode p) block.next[p._idx] = blocks.get(p);
-                    break;
-                case RegionNode r:
-                    block.next[0] = blocks.get(r);
-                    break;
-                default:
-                    assert block.exit instanceof ReturnNode;
-            }
-        }
-        // And return the block for the start node.
-        return blocks.get(start);
-    }
-
-    /**
-     * Create a schedule for the program reachable from start.
-     * @param start The start node
-     * @return The final schedule.
-     */
-    public static Scheduler.Block schedule(StartNode start) {
-        var scheduler = new Scheduler();
-        scheduler.doMarkAlive(start);
-        scheduler.doBuildCTF(start);
-        scheduler.doSchedule();
-        return scheduler.build(start);
-    }
-
-}
diff --git a/chapter10/src/test/java/com/seaofnodes/simple/fuzzer/Fuzzer.java b/chapter10/src/test/java/com/seaofnodes/simple/fuzzer/Fuzzer.java
deleted file mode 100644
index 7dcb88e5..00000000
--- a/chapter10/src/test/java/com/seaofnodes/simple/fuzzer/Fuzzer.java
+++ /dev/null
@@ -1,199 +0,0 @@
-package com.seaofnodes.simple.fuzzer;
-
-import com.seaofnodes.simple.Parser;
-import com.seaofnodes.simple.evaluator.Evaluator;
-import com.seaofnodes.simple.node.Node;
-import com.seaofnodes.simple.node.StopNode;
-
-import java.util.ArrayList;
-import java.util.Objects;
-import java.util.Random;
-import java.util.function.Consumer;
-
-/**
- * Implementation of the fuzzer.
- * Random testcases are generated using the ScriptGenerator.
- * This will generate a script similar to how the parser parses it but instead of parsing it will
- * randomly choose a variation the parser would parse and generate it.
- * These scripts are the parsed by the parser and all exceptions are caught and filtered
- * to only show one occurrence of one problem. This includes script which generate different
- * results when graphs optimized with different worklist seeds are executed.
- * To aid debugging scripts that cause errors are then reduced by applying rules and checking
- * that the same issue persists.
- */
-public class Fuzzer {
-
-    private static final int EVAL_TIMEOUT = 1000;
-
-    /**
-     * List of exceptions already encountered.
-     * This is used to filter new exceptions and discard them if they are already found.
-     */
-    private final ArrayList<Throwable> exceptions = new ArrayList<>();
-
-    /**
-     * Filter and record an exception in a script.
-     * @param e The exception caused by the script
-     * @param script The script causing the exception
-     * @param reproducer Reproducer which should be used to reproduce the test case.
-     */
-    private void recordException(Throwable e, String script, Consumer<String> reproducer, long seed) {
-        for (var ex : exceptions) {
-            if (FuzzerUtils.isExceptionFromSameCause(ex, e)) return;
-        }
-        exceptions.add(e);
-        System.out.println("========== Stack ==========");
-        e.printStackTrace(System.out);
-        System.out.println("========== Seed ==========");
-        System.out.println(seed);
-        System.out.println("========== Code ===========");
-        System.out.println(script);
-        System.out.println("========= Reduced =========");
-        System.out.println(Reducer.reduce(script, e, reproducer));
-        System.out.println("===========================");
-        System.out.flush();
-    }
-
-    private static boolean neq(Object a, Object b) {
-        if (Objects.equals(a, b)) return false;
-        if (a instanceof Evaluator.Obj ea && b instanceof Evaluator.Obj eb) {
-            if (ea.struct() != eb.struct()) return true;
-            for(int i=0;i<ea.fields().length;i++) {
-                if (neq(ea.fields()[i], eb.fields()[i])) return true;
-            }
-            return false;
-        }
-        return true;
-    }
-
-    /**
-     * Check that two graphs result in the same output when supplied with a value
-     * @param e1 Evaluator for the first graph
-     * @param e2 Evaluator for the second graph
-     * @param in The input value to both graphs to test for an equal output
-     */
-    private static void checkGraphs(Evaluator e1, Evaluator e2, long in) {
-        var r1 = e1.evaluate(in, EVAL_TIMEOUT);
-        var r2 = e2.evaluate(in, EVAL_TIMEOUT);
-        if (r1 == Evaluator.Status.TIMEOUT || r2 == Evaluator.Status.TIMEOUT) return;
-        if (neq(r1, r2))
-            throw new RuntimeException("Different calculations values " + r1 + " vs " + r2);
-    }
-
-    /**
-     * Run checks for script. Compile the script with two different optimizer worklist seeds.
-     * Check that exceptions raised in the parser by both methods are the same and only happens if the script may be invalid.
-     * If the script was successfully parsed check that both version behave the same.
-     * @param script The script to test
-     * @param valid If the script is definitely valid. If not some exceptions may be suppressed.
-     */
-    private static void runCheck(String script, boolean valid) {
-        StopNode stop1;
-        try {
-            stop1 = FuzzerUtils.parse(script, 123);
-        } catch (RuntimeException e1) {
-            try {
-                FuzzerUtils.parse(script, 456);
-            } catch (RuntimeException e2) {
-                if (FuzzerUtils.isExceptionFromSameCause(e1, e2)) {
-                    if (!valid || e1.getClass() == RuntimeException.class) return;
-                } else {
-                    e1.addSuppressed(e2);
-                }
-            }
-            throw e1;
-        }
-        var stop2 = FuzzerUtils.parse(script, 456);
-        var e1 = new Evaluator(stop1);
-        var e2 = new Evaluator(stop2);
-        checkGraphs(e1, e2, 0);
-        checkGraphs(e1, e2, 1);
-        checkGraphs(e1, e2, 10);
-    }
-
-    /**
-     * Check that the script does not result in exceptions.
-     * @param script The script to test.
-     * @param valid If the script is valid or if it might contain syntax errors.
-     */
-    private void check(String script, boolean valid, long seed) {
-        try {
-            runCheck(script, valid);
-        } catch (Throwable e) {
-            recordException(e, script, s->runCheck(s, valid), seed);
-        }
-    }
-
-    /**
-     * Run one test with the given seed, and check for peephole counts.
-     * @param seed The seed to use for generating this test case
-     */
-    public int fuzzPeepTiming(long seed, int max_nids) {
-        var rand = new Random(seed);
-        var sb = new StringBuilder();
-        new ScriptGenerator(rand, sb, true).genProgram();
-        try {
-            var parser = new Parser(sb.toString());
-
-            var stop = parser.parse();
-            int parse_peeps= Node.ITER_CNT;
-            int parse_nops = Node.ITER_NOP_CNT;
-            double parse_nop_ratio = (double)parse_nops/parse_peeps;
-            int nids = Node.UID();
-            if( nids <= max_nids ) return max_nids;
-
-            double parse_peeps_per_node = (double)parse_peeps/nids;
-
-            stop.iterate();
-            int iter_peeps= Node.ITER_CNT;
-            int iter_nops = Node.ITER_NOP_CNT;
-            double iter_nop_ratio = (double)iter_nops/iter_peeps;
-            double iter_peeps_per_node = (double)iter_peeps/nids;
-
-            System.out.printf("%6d | Parsing: peeps: %5d, nops: %5d, ratio: %5.3f, last UID: %5d ps/node: %5.3f  | Iter: peeps: %6d, nops: %6d, ratio: %5.3f, ps/node: %5.3f\n",
-                              seed,
-                              parse_peeps,parse_nops,parse_nop_ratio,nids,parse_peeps_per_node,
-                              iter_peeps , iter_nops, iter_nop_ratio,      iter_peeps_per_node);
-            return nids;
-        } catch (Throwable e) {
-            // ignore exceptions, let the normal fullPeeps catch and reduce,
-            // we're interested in valid program optimizations
-        }
-        return max_nids;
-    }
-
-
-    /**
-     * Run one test with the given seed.
-     * @param seed The seed to use for generating this test case
-     */
-    public void fuzzPeeps(long seed) {
-        var rand = new Random(seed);
-        var sb = new StringBuilder();
-        var valid = new ScriptGenerator(rand, sb, true).genProgram();
-        check(sb.toString(), valid, seed);
-    }
-
-
-    /**
-     * Check that no exceptions happened.
-     * @return true if no exception happened
-     */
-    public boolean noExceptions() {
-        return exceptions.isEmpty();
-    }
-
-    /** Run a fixed chapter-local seed without reducing or swallowing failures. */
-    public void fuzzPeepsRegression(long seed) {
-        var rand = new Random(seed);
-        var sb = new StringBuilder();
-        var valid = new ScriptGenerator(rand, sb, true).genProgram();
-        try {
-            runCheck(sb.toString(), valid);
-        } catch (Throwable e) {
-            AssertionError ae = new AssertionError("Fuzzer regression seed failed: " + seed);
-            ae.initCause(e);
-            throw ae;
-        }
-    }
-}
diff --git a/chapter10/src/test/java/com/seaofnodes/simple/fuzzer/FuzzerUtils.java b/chapter10/src/test/java/com/seaofnodes/simple/fuzzer/FuzzerUtils.java
deleted file mode 100644
index f947a234..00000000
--- a/chapter10/src/test/java/com/seaofnodes/simple/fuzzer/FuzzerUtils.java
+++ /dev/null
@@ -1,142 +0,0 @@
-package com.seaofnodes.simple.fuzzer;
-
-import com.seaofnodes.simple.IterPeeps;
-import com.seaofnodes.simple.Parser;
-import com.seaofnodes.simple.node.Node;
-import com.seaofnodes.simple.node.StopNode;
-
-import java.io.OutputStream;
-import java.io.PrintStream;
-import java.lang.invoke.MethodHandle;
-import java.lang.invoke.MethodHandles;
-import java.lang.reflect.Field;
-import java.util.BitSet;
-
-/**
- * Some utilities for the fuzzer.
- */
-class FuzzerUtils {
-
-    /**
-     * Get the val of a private field
-     */
-    @SuppressWarnings("unchecked")
-    public static <T> T getFieldValue(Object obj, String name) throws NoSuchFieldException, IllegalAccessException {
-        return (T) (obj instanceof Class<?> clz ? getField(clz, name).get(null) : getField(obj.getClass(), name).get(obj));
-    }
-
-    /**
-     * Get access to a private field
-     */
-    public static Field getField(Class<?> clz, String name) throws NoSuchFieldException {
-        var field = clz.getDeclaredField(name);
-        try {
-            field.setAccessible(true);
-        } catch (Throwable e) {
-            // Intentionally left empty
-        }
-        return field;
-    }
-
-    /**
-     * Try to rethrow an exception or create a runtime exception and throw it.
-     */
-    public static RuntimeException rethrow(Throwable e) {
-        if (e instanceof RuntimeException re) return re;
-        if (e instanceof Error er) throw er;
-        return new RuntimeException(e);
-    }
-
-    /**
-     * Copy of Node.WVISIST
-     * Used to clear as exceptions might happen in the walk and left this bitset not cleared
-     */
-    private static final BitSet NodeWalkVisit;
-    private static final java.util.Random WorkRandom;
-
-    /**
-     * Write access to Iterate.MID_ASSERT
-     * Exception could happen mid assert and left this at true. Used to reset to false prior to parsing.
-     */
-    private static final MethodHandle set_MID_ASSERT;
-
-    /**
-     * Some problems might trigger debug output. Suppress this output with a null print stream during fuzzing.
-     */
-    public static final PrintStream NULL_PRINT_STREAM = new PrintStream(OutputStream.nullOutputStream());
-
-    static {
-        try {
-            NodeWalkVisit = getFieldValue(Node.class, "WVISIT");
-            WorkRandom = getFieldValue(getFieldValue(IterPeeps.class, "WORK"), "_R");
-            set_MID_ASSERT = MethodHandles.lookup().unreflectSetter(getField( IterPeeps.class, "MID_ASSERT"));
-        } catch (Exception e) {
-            throw new ExceptionInInitializerError(e);
-        }
-    }
-
-    /**
-     * Check that the messages are similar.
-     */
-    private static boolean similarMessages(String a, String b) {
-        if (a == null || b == null) return true;
-        a = a.replaceAll("'\\w+'", "'normalized'").replaceAll("variable \\w+", "variable normalized");
-        b = b.replaceAll("'\\w+'", "'normalized'").replaceAll("variable \\w+", "variable normalized");
-        return a.equals(b);
-    }
-
-    /**
-     * Check if both stack traces have the same first entry. Empty stack traces can happen with NPE optimization
-     * and allow the other to be any stack trace.
-     */
-    private static boolean sameStackTraceOrigin(StackTraceElement[] a, StackTraceElement[] b) {
-        if (a == null || a.length == 0 || b == null || b.length == 0) return true; // One or both stack traces are missing.
-        return a[0].equals(b[0]);
-    }
-
-    /**
-     * Checks if two exceptions are caused by the same problem.
-     */
-    public static boolean isExceptionFromSameCause(Throwable a, Throwable b) {
-        if (a == null || b == null) return a == b; // Handle the null case
-        if (a.getClass() != b.getClass()) return false; // Different classes
-        if (!similarMessages(a.getMessage(), b.getMessage())) return false; // Different messages. Null is allowed as wildcard
-        var s1 = a.getStackTrace();
-        var s2 = b.getStackTrace();
-        if (!sameStackTraceOrigin(s1, s2)) return false; // Different stack trace origins
-        if (!isExceptionFromSameCause(a.getCause(), b.getCause())) return false; // Different causes
-        var o1 = a.getSuppressed();
-        var o2 = b.getSuppressed();
-        if (o1 == null || o2 == null || o1.length != o2.length) return o1 == o2; // Different suppression
-        for (int i=0; i<o1.length; i++) {
-            if (!isExceptionFromSameCause(o1[i], o2[i])) return false; // Different suppression
-        }
-        return true;
-    }
-
-    /**
-     * Parse and optimize using the given worklist seed
-     */
-    public static StopNode parse(String script, long workListSeed) {
-        var err = System.err;
-        var out = System.out;
-        try {
-            System.setErr(NULL_PRINT_STREAM);
-            System.setOut(NULL_PRINT_STREAM);
-            try {
-                set_MID_ASSERT.invokeExact(false);
-            } catch (Throwable e) {
-                throw rethrow(e);
-            }
-            var parser = new Parser(script);
-            WorkRandom.setSeed(workListSeed);
-            var stop = parser.parse();
-            return stop.iterate();
-        } finally {
-            NodeWalkVisit.clear();
-            System.setErr(err);
-            System.setOut(out);
-        }
-    }
-
-}
diff --git a/chapter10/src/test/java/com/seaofnodes/simple/fuzzer/Reducer.java b/chapter10/src/test/java/com/seaofnodes/simple/fuzzer/Reducer.java
deleted file mode 100644
index 3731b40c..00000000
--- a/chapter10/src/test/java/com/seaofnodes/simple/fuzzer/Reducer.java
+++ /dev/null
@@ -1,176 +0,0 @@
-package com.seaofnodes.simple.fuzzer;
-
-import java.util.Arrays;
-import java.util.function.BiConsumer;
-import java.util.function.Consumer;
-import java.util.function.Predicate;
-import java.util.regex.Matcher;
-import java.util.regex.Pattern;
-
-/**
- * This class is used to reduce test cases created by the fuzzer.
- * It applies rewrite rules to the test case and checks that the
- * test still produces the same exception.
- * This is done in a fixpoint iteration until every rewrite produces
- * no or a different exception.
- */
-public class Reducer {
-
-    private interface Replacer extends BiConsumer<StringBuilder, Matcher> {}
-
-    /**
-     * Holder for the rewrite rules
-     */
-    private record Replace(Pattern pattern, boolean iterate, Replacer... replacements) {
-        Replace(Pattern p, Object... replacements) {
-            this(p, replacements[0] == Boolean.TRUE, Arrays.stream(replacements).filter(o->!(o instanceof Boolean)).map(Replace::from).toArray(Replacer[]::new));
-        }
-        private static Replacer from(Object o) {
-            if (o instanceof Replacer r) return r;
-            if (o instanceof Integer i) return (s, m)->s.append(m.group(i));
-            if (o instanceof String r) return (s, m)->s.append(r);
-            throw new IllegalArgumentException();
-        }
-    }
-
-    /**
-     * List of rewrite rules.
-     */
-    private static final Replace[] REPLACEMENTS = {
-            new Replace(Pattern.compile("\\b(?:[^\\W0]|\\w\\w+)\\b"), "0", "1"),
-            new Replace(Pattern.compile("(?<=\\n|^)[^\\n]+(?=\\n|$)"), true, ""),
-            new Replace(Pattern.compile("(?<=[+\\-*/<>=(])--"), ""),
-            new Replace(Pattern.compile("\\b--"), "+"),
-            new Replace(Pattern.compile("-"), ""),
-            new Replace(Pattern.compile("\\b\\+-"), "-"),
-            new Replace(Pattern.compile("(?<![+\\-*/<>=])(?:-|\\*|/|>=|<=|>|<|!=|==)(?![+\\-*/<>=])"), "+"),
-            new Replace(Pattern.compile("\\{((?:[^{}]|\\{})+)(?:\\n[ \\t]*)?}"), "", "{}", 1),
-            new Replace(Pattern.compile("(?<=\\n|^)([ \\t]*)\\{\\n(.*?)\\n\\1}", Pattern.DOTALL), 2),
-            new Replace(Pattern.compile("\\(([^()]+)\\)"), 1),
-            new Replace(Pattern.compile("\\d+\\+"), ""),
-            new Replace(Pattern.compile("\\+\\d+"), ""),
-            new Replace(Pattern.compile("\\n\\n+"), "\n"),
-            new Replace(Pattern.compile("^\\n+|\\n+$"), ""),
-            new Replace(Pattern.compile("else *"), ""),
-            new Replace(Pattern.compile("\\bif\\([^()]+\\) *"), ""),
-            new Replace(Pattern.compile("\\bwhile\\([^()]+\\) *"), ""),
-            new Replace(Pattern.compile("\\bstruct \\w+ \\{[^{}]*}"), "")
-    };
-
-    /**
-     * Predicate to test if the reduced script generates the same error.
-     */
-    private final Predicate<String> tester;
-
-    /**
-     * Create a reducer with a test function.
-     * @param tester Test function which returns true when the same issue is found in the script.
-     */
-    private Reducer(Predicate<String> tester) {
-        this.tester = tester;
-    }
-
-    /**
-     * Rewrites the script with one rewrite rule.
-     */
-    private String doReplacement(String script, Pattern pattern, Replacer[] replacements) {
-        var matcher = pattern.matcher(script);
-        var sb = new StringBuilder();
-        var last = 0;
-        var skip = 0;
-        outer:
-        while (matcher.find(last + skip)) {
-            sb.append(script, last, matcher.start());
-            last = matcher.end();
-            skip = last == matcher.start() ? 1 : 0;
-            var pos = sb.length();
-            for (var replacement : replacements) {
-                replacement.accept(sb, matcher);
-                var tail = sb.length();
-                sb.append(script, last, script.length());
-                if (tester.test(sb.toString())) {
-                    sb.setLength(tail);
-                    continue outer;
-                }
-                sb.setLength(pos);
-            }
-            last = matcher.start();
-            skip = 1;
-        }
-        sb.append(script, last, script.length());
-        return sb.toString();
-    }
-
-    /**
-     * Clean up variable names from the random ones generated by the fuzzer.
-     */
-    private String cleanVariables(String script) {
-        var matcher = Pattern.compile("\\b([0-9a-zA-Z_]+) ([0-9a-zA-Z_]+)").matcher(script);
-        int[] num = {0, 0};
-        while (matcher.find()) {
-            var type = matcher.group(1);
-            var var = matcher.group(2);
-            if (type.equals("new")) continue;
-            String prefix = "v";
-            int t = 0;
-            if (type.equals("struct")) {
-                t = 1;
-                prefix = "s";
-            }
-            if (var.matches(prefix+"\\d+")) continue;
-            while (script.contains(prefix+num[t])) num[t]++;
-            var n = script.replaceAll("\\b"+var+"\\b", prefix + num[t]);
-            if (tester.test(n)) {
-                script = n;
-            }
-        }
-        return script;
-    }
-
-    /**
-     * Run all rewrite rules once.
-     */
-    private String doAllReplacements(String script) {
-        for (var replace: REPLACEMENTS) {
-            String old;
-            do {
-                old = script;
-                script = doReplacement(script, replace.pattern, replace.replacements);
-            } while (replace.iterate && !old.equals(script));
-        }
-        return script;
-    }
-
-    /**
-     * Reduce the script to a minimal version which produces the same problem with a test function.
-     * @param tester Test function which returns true when the same issue is found in the script.
-     */
-    public static String reduce(String script, Predicate<String> tester) {
-        var reducer = new Reducer(tester);
-        String old;
-        do {
-            old = script;
-            script = reducer.doAllReplacements(script);
-            script = reducer.cleanVariables(script);
-        } while (!script.equals(old));
-        return script;
-    }
-
-    /**
-     * Reduce the script to a minimal version which produces the same problem with a reproducer.
-     * @param ex The exception originally caused by the script
-     * @param reproducer Test function which throws an exception which will be checked against ex.
-     */
-    public static String reduce(String script, Throwable ex, Consumer<String> reproducer) {
-        return reduce(script, s->{
-            Throwable nex = null;
-            try {
-                reproducer.accept(s);
-            } catch (Throwable e) {
-                nex = e;
-            }
-            return FuzzerUtils.isExceptionFromSameCause(nex, ex);
-        });
-    }
-
-}
diff --git a/chapter10/src/test/java/com/seaofnodes/simple/fuzzer/ScriptGenerator.java b/chapter10/src/test/java/com/seaofnodes/simple/fuzzer/ScriptGenerator.java
deleted file mode 100644
index 155063ab..00000000
--- a/chapter10/src/test/java/com/seaofnodes/simple/fuzzer/ScriptGenerator.java
+++ /dev/null
@@ -1,792 +0,0 @@
-package com.seaofnodes.simple.fuzzer;
-
-import com.seaofnodes.simple.Parser;
-import com.seaofnodes.simple.node.ScopeNode;
-
-import java.util.ArrayList;
-import java.util.HashSet;
-import java.util.Random;
-import java.util.function.Predicate;
-
-/**
- * Generate a pseudo random script.
- * This generator will generate the same script for two random number generators initialized with the same seed.
- * To generate valid code it implements the parser but instead of parsing it emits the statements and expressions.
- * It is guaranteed to terminate.
- */
-public class ScriptGenerator {
-
-    private static final int MAX_STATEMENTS_PER_BLOCK = 5;
-    private static final int MAX_BINARY_EXPRESSIONS_PER_EXPRESSION = 10;
-    private static final int MAX_UNARY_EXPRESSIONS_PER_EXPRESSION = 6;
-    private static final int MAX_NAME_LENGTH = 10;
-    private static final int MAX_BLOCK_DEPTH = 4;
-    private static final int MAX_EXPRESSION_DEPTH = 10;
-
-    /**
-     * Number of spaces per indentation
-     */
-    private static final int INDENTATION = 4;
-    /**
-     * Valid characters for identifiers. The last 10 are not valid for the first character.
-     */
-    private static final String VAR_CHARS = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ_0123456789";
-    /**
-     * List of keywords not valid for identifiers.
-     */
-    private static final HashSet<String> KEYWORDS;
-
-    static {
-        try {
-            KEYWORDS = FuzzerUtils.getFieldValue(new Parser(""), "KEYWORDS");
-        } catch (Throwable e) {
-            throw new ExceptionInInitializerError(e);
-        }
-    }
-
-    /**
-     * Flag for a statement that it does not pass on control flow to the next statement.
-     */
-    private static final int FLAG_STOP = 0x01;
-    /**
-     * Flag for a statement that it contains a final if statement without an else branch.
-     */
-    private static final int FLAG_IF_WITHOUT_ELSE = 0x02;
-    /**
-     * Binary operators.
-     */
-    private static final String[] BINARY_OP = {"==", "!=", "<", "<=", ">", ">=", "+", "-", "*", "/"};
-    /**
-     * Unary operators.
-     */
-    private static final String[] UNARY_OP = {"-"};
-
-    private static class Type {
-        final String name;
-        Type(String name) {this.name=name;}
-        boolean isa(Type other) { return this == other; }
-    }
-
-    private static class TypeStruct extends Type {
-        record Field (String name, Type type) {}
-        final Field[] fields;
-        final TypeNullable nullable = new TypeNullable(this);
-        TypeStruct(String name, Field[] fields) {
-            super(name);
-            this.fields = fields;
-        }
-        boolean isa(Type other) { return this == other || other == nullable; }
-    }
-
-    private static class TypeNullable extends Type {
-
-        final Type base;
-
-        TypeNullable(Type base) {
-            super(base.name+"?");
-            this.base = base;
-        }
-
-    }
-
-    private static final Type TYPE_INT = new Type("int");
-
-
-    private static class Variable {
-        final String name;
-        final Type declared;
-        final Variable shadowing;
-        Type type;
-        boolean shadowed = false;
-
-        Variable(String name, Type type, Variable var) {
-            this.name = name;
-            this.declared = type;
-            this.type = type;
-            this.shadowing = var;
-        }
-    }
-
-    /**
-     * The random number generator used for random decisions.
-     */
-    private final Random random;
-    /**
-     * Indentation depth.
-     */
-    private int indentation = 0;
-    /**
-     * Output string builder
-     */
-    private final StringBuilder sb;
-    /**
-     * Number of nested loops
-     */
-    private int loopDepth = 0;
-    /**
-     * Current scope start in the variables list.
-     */
-    private int currScopeStart = 0;
-    /**
-     * The depth of blocks allowed.
-     */
-    private int depth = MAX_BLOCK_DEPTH;
-    /**
-     * The depth of expressions allowed.
-     */
-    private int exprDepth = MAX_EXPRESSION_DEPTH;
-    /**
-     * Current variables in scope.
-     */
-    private final ArrayList<Variable> variables = new ArrayList<>();
-    /**
-     * All defined structs.
-     */
-    private final ArrayList<TypeStruct> structs = new ArrayList<>();
-    /**
-     * Allow to declare structs.
-     */
-    private boolean allowStructs = true;
-    /**
-     * If this needs to generate valid scripts or is also allowed to generate invalid ones.
-     */
-    private boolean generateValid;
-    /**
-     * If this script might be invalid.
-     */
-    private boolean maybeInvalid = false;
-
-
-    /**
-     *
-     * @param random the random number generator.
-     * @param sb the script will be written to this string builder.
-     * @param generateValid if the script should be guaranteed valid or if it is allowed to contain bugs.
-     */
-    public ScriptGenerator(Random random, StringBuilder sb, boolean generateValid) {
-        this.random = random;
-        this.sb = sb;
-        this.generateValid = generateValid;
-    }
-
-    /**
-     * Random number with log distribution
-     * @param max The maximum value
-     * @return A random number in the range [0, max) with higher numbers being more uncommon.
-     */
-    private int randLog(int max) {
-        max--;
-        int n = 1<<max;
-        var num = random.nextInt(n);
-        for (int i=max-1; i>=0; i--) {
-            if ((num & (1<<i))!=0) return max-i-1;
-        }
-        return max;
-    }
-
-    /**
-     * Helper function to print indentation.
-     * @return sb for chaining
-     */
-    private StringBuilder printIndentation() {
-        return sb.repeat(' ', indentation);
-    }
-
-    /**
-     * Generate a random name for variables. This might be invalid when it is a keyword.
-     * @return The random name generated
-     */
-    private StringBuilder getRandomName() {
-        int len = random.nextInt(MAX_NAME_LENGTH) + 1;
-        StringBuilder sb = new StringBuilder(len);
-        sb.append(VAR_CHARS.charAt(random.nextInt(VAR_CHARS.length()-10)));
-        for (int i=1; i<len; i++)
-            sb.append(VAR_CHARS.charAt(random.nextInt(VAR_CHARS.length())));
-        return sb;
-    }
-
-    /**
-     * Should invalid code be generated?
-     * @return True if invalid code should be generated
-     */
-    private boolean generateInvalid() {
-        if (generateValid || random.nextInt(1000)>2) return false;
-        maybeInvalid = true;
-        return true;
-    }
-
-    /**
-     * Lookup a variable by name
-     * @param name name of the variable
-     * @return The index of the variable in variables or -1
-     */
-    private int lookup(String name) {
-        for (int i=variables.size()-1; i>=0; i--) {
-            if (variables.get(i).name.equals(name)) return i;
-        }
-        return -1;
-    }
-
-    /**
-     * Lookup a variable by name
-     * @param name name of the variable
-     * @return THe variable of null if not found
-     */
-    private Variable lookupVar(String name) {
-        int idx = lookup(name);
-        return idx == -1 ? null : variables.get(idx);
-    }
-
-    /**
-     * Add a variable to the current scope
-     * @param name The name of the variable
-     * @param type The declared type of the variable
-     */
-    private void addVariable(String name, Type type) {
-        var old = lookupVar(name);
-        variables.add(new Variable(name, type, old));
-        if (old != null) old.shadowed = true;
-    }
-
-    /**
-     * Pop variables to level to
-     * @param to Level until which variables should be popped
-     */
-    private void popVariables(int to) {
-        while (variables.size() > to) {
-            var v = variables.removeLast();
-            if (v.shadowing != null) v.shadowing.shadowed = false;
-        }
-    }
-
-    /**
-     * Get a random visible variable patching pred
-     * @param pred The predicate the variable needs to match
-     * @return A random visible variable matching pred or null if no variable mached pred.
-     */
-    private Variable findVisibleVariablesMatching(Predicate<Variable> pred) {
-        int num=0;
-        for (var v:variables) {
-            if (!v.shadowed && pred.test(v)) num++;
-        }
-        if (num == 0) return null;
-        num = random.nextInt(num);
-        for (var v:variables) {
-            if (!v.shadowed && pred.test(v) && num-- == 0) return v;
-        }
-        throw new AssertionError();
-    }
-
-    /**
-     * Get a structure by name
-     * @param name Name of the structure
-     * @return The structure of null
-     */
-    private TypeStruct getStruct(String name) {
-        for (var s:structs) {
-            if (s.name.equals(name)) return s;
-        }
-        return null;
-    }
-
-    /**
-     * Generate a variable name. This might be new random name or a name from an outer scope.
-     * If the program is allowed to be invalid this can return keywords and already used variable names in the current scope.
-     * @return The variable name.
-     */
-    private String getVarName() {
-        if (currScopeStart > 0 && random.nextInt(10) > 7) {
-            // Use a variable outside the current scope.
-            var v = variables.get(random.nextInt(currScopeStart));
-            if (lookup(v.name) < currScopeStart) return v.name;
-            if (!generateValid) {
-                maybeInvalid = true;
-                return v.name;
-            }
-        }
-        // Generate a new random variable name
-        StringBuilder sb = getRandomName();
-        var v = sb.toString();
-        if (!generateValid && (KEYWORDS.contains(v) || lookup(v) >= currScopeStart)) {
-            maybeInvalid = true;
-            return v;
-        }
-        while (KEYWORDS.contains(v) || lookup(v) >= currScopeStart) {
-            sb.append(VAR_CHARS.charAt(random.nextInt(VAR_CHARS.length())));
-            v = sb.toString();
-        }
-        return v;
-    }
-
-    /**
-     * Get a random structure name
-     * @return A random structure name
-     */
-    private String getStructName() {
-        if (!structs.isEmpty() && generateInvalid()) return structs.get(random.nextInt(structs.size())).name;
-        // Generate a new random struct name
-        StringBuilder sb = getRandomName();
-        var v = sb.toString();
-        if (!generateValid && (KEYWORDS.contains(v) || getStruct(v) != null)) {
-            maybeInvalid = true;
-            return v;
-        }
-        while (KEYWORDS.contains(v) || getStruct(v) != null) {
-            sb.append(VAR_CHARS.charAt(random.nextInt(VAR_CHARS.length())));
-            v = sb.toString();
-        }
-        return v;
-    }
-
-    /**
-     * Get a random type
-     * @return A random type
-     */
-    private Type getType() {
-        if (structs.isEmpty() || random.nextBoolean()) return TYPE_INT;
-        var idx = random.nextInt(structs.size());
-        TypeStruct struct = structs.get(idx);
-        if (random.nextBoolean()) return struct.nullable;
-        return struct;
-    }
-
-    /**
-     * Generates a program and writes it into the string builder supplied in the constructor.
-     * @return If the program is allowed to be invalid returns if something potentially invalid was generated.
-     */
-    public boolean genProgram() {
-        var oldGenerateValid = generateValid;
-        if (!generateValid && random.nextBoolean()) generateValid = true;
-        this.maybeInvalid = false;
-        addVariable(ScopeNode.ARG0, TYPE_INT);
-        currScopeStart = variables.size();
-        if ((genStatements() & FLAG_STOP) == 0) {
-            if (generateValid || random.nextInt(10)<7) {
-                genReturn();
-            } else {
-                this.maybeInvalid = true;
-            }
-        }
-        generateValid = oldGenerateValid;
-        return !this.maybeInvalid;
-    }
-
-    /**
-     * Generate a list of statements.
-     * @return flags FLAG_STOP and FLAG_IF_WITHOUT_ELSE for the last statement generated
-     */
-    public int genStatements() {
-        var num = random.nextInt(MAX_STATEMENTS_PER_BLOCK * (depth+1));
-        for (int i=0; i<num; i++) {
-            printIndentation();
-            var stop = genStatement();
-            sb.append("\n");
-            if ((stop & FLAG_STOP) != 0) return stop;
-        }
-        return 0;
-    }
-
-    /**
-     * Generate a single statement
-     * @return flags FLAG_STOP and FLAG_IF_WITHOUT_ELSE for the generated statement
-     */
-    public int genStatement() {
-        return switch (random.nextInt(12)) {
-            case 0 -> allowStructs || generateInvalid() ? genStruct() : genAssignment();
-            case 1 -> genBlock();
-            case 2 -> genIf();
-            case 3 -> genCountedLoop();
-            case 4 -> genWhile();
-            case 5, 6 -> genDecl();
-            case 7, 8, 9 -> genAssignment();
-            case 10 -> genNullCheck();
-            default -> genExit();
-        };
-    }
-
-    /**
-     * Generate a new structure
-     * @return 0
-     */
-    public int genStruct() {
-        var name = getStructName();
-        var fields = new TypeStruct.Field[generateInvalid() ? 0 : random.nextInt(10)];
-        sb.append("struct ").append(name).append(" {\n");
-        indentation += INDENTATION;
-        for (int i=0; i<fields.length; i++) {
-            var fieldName = getRandomName();
-            var type = generateInvalid() ? getType() : TYPE_INT;
-            printIndentation().append(type.name).append(" ").append(fieldName).append(";\n");
-            fields[i] = new TypeStruct.Field(fieldName.toString(), type);
-        }
-        indentation -= INDENTATION;
-        printIndentation().append("}");
-        structs.add(new TypeStruct(name, fields));
-        return 0;
-    }
-
-    /**
-     * Generate a statement for if, else and while blocks.
-     * This is special since it disallows declarations and prefers to generate blocks.
-     * @return flags FLAG_STOP and FLAG_IF_WITHOUT_ELSE for the generated statement
-     */
-    public int genStatementBlock() {
-        var oldAllowStructs = allowStructs;
-        allowStructs = false;
-        indentation += INDENTATION;
-        int res;
-        if (depth == 0) {
-            res = random.nextBoolean() ? genAssignment() : genExit();
-        } else {
-            depth--;
-            res = switch (random.nextInt(12)) {
-                case 1, 2, 3, 4, 5 -> {
-                    depth++;
-                    indentation -= INDENTATION;
-                    var ret = genBlock();
-                    indentation += INDENTATION;
-                    depth--;
-                    yield ret;
-                }
-                case 6 -> genIf();
-                case 7 -> genCountedLoop();
-                case 8 -> genWhile();
-                case 9 -> genAssignment();
-                case 10 -> genNullCheck();
-                default -> genExit();
-            };
-            depth++;
-        }
-        indentation -= INDENTATION;
-        allowStructs = oldAllowStructs;
-        return res;
-    }
-
-    /**
-     * Generate an exit. This can be return or break and continue when in a loop.
-     * @return FLAG_STOP
-     */
-    public int genExit() {
-        if (loopDepth == 0 && generateValid) return genReturn();
-        return switch (random.nextInt(7)) {
-            case 0,1,2 -> {
-                if (loopDepth == 0) maybeInvalid = true;
-                sb.append("continue;");
-                yield FLAG_STOP;
-            }
-            case 3,4,5 -> {
-                if (loopDepth == 0) maybeInvalid = true;
-                sb.append("break;");
-                yield FLAG_STOP;
-            }
-            default -> genReturn();
-        };
-    }
-
-    /**
-     * Generate a block statement. After a certain depth only empty blocks are generated to ensure termination of the generator.
-     * @return flag FLAG_STOP for the generated statement
-     */
-    public int genBlock() {
-        if (depth == 0) {
-            sb.append("{}");
-            return 0;
-        }
-        var oldAllowStructs = allowStructs;
-        var oldCSS = currScopeStart;
-        allowStructs = false;
-        currScopeStart = variables.size();
-        depth--;
-        sb.append("{\n");
-        indentation += INDENTATION;
-        var stop = genStatements();
-        indentation -= INDENTATION;
-        printIndentation().append("}");
-        popVariables(currScopeStart);
-        depth++;
-        currScopeStart = oldCSS;
-        allowStructs = oldAllowStructs;
-        return stop & ~FLAG_IF_WITHOUT_ELSE;
-    }
-
-    /**
-     * Generate an if statement with an optional else block.
-     * @return flags FLAG_STOP and FLAG_IF_WITHOUT_ELSE for the generated statement
-     */
-    public int genIf() {
-        sb.append("if(");
-        genExpression(TYPE_INT);
-        sb.append(") ");
-        var stop = genStatementBlock();
-        if ((stop & FLAG_IF_WITHOUT_ELSE) == 0 && random.nextInt(10) > 3) {
-            sb.append("\n");
-            printIndentation().append("else ");
-            stop &= genStatementBlock();
-        } else {
-            stop = FLAG_IF_WITHOUT_ELSE;
-        }
-        return stop;
-    }
-
-    /**
-     * Generate a block with a null check
-     * if (nullable) { handle_nullable_as_non_nullable; }
-     */
-    public int genNullCheck() {
-        var v = findVisibleVariablesMatching(va->va.declared instanceof TypeNullable);
-        if (v == null) return genIf();
-        var n = (TypeNullable)v.declared;
-        boolean negate = random.nextBoolean();
-        sb.append("if(");
-        if (negate) sb.append("!");
-        sb.append(v.name).append(")");
-        if (!negate) v.type = n.base;
-        var stop = genStatementBlock();
-        v.type = n;
-        if ((stop & FLAG_IF_WITHOUT_ELSE) == 0 && random.nextInt(10) > 3) {
-            sb.append("\n");
-            printIndentation().append("else ");
-            if (negate) v.type = n.base;
-            stop &= genStatementBlock();
-            v.type = n;
-        } else {
-            stop = FLAG_IF_WITHOUT_ELSE;
-        }
-        return stop;
-    }
-
-    /**
-     * Generate a while loop.
-     * @return 0
-     */
-    public int genWhile() {
-        sb.append("while(");
-        genExpression(TYPE_INT);
-        sb.append(") ");
-        loopDepth++;
-        genStatementBlock();
-        loopDepth--;
-        return 0;
-    }
-
-    /**
-     * Generate a counted loop of the form
-     * <code>
-     *     {
-     *         int varname = start_expr;
-     *         while (varname < end_expr) loop_body;
-     *     }
-     * </code>
-     * @return 0
-     */
-    public int genCountedLoop() {
-        if (depth == 0) return genWhile();
-        var oldCSS = currScopeStart;
-        currScopeStart = variables.size();
-        sb.append("{\n");
-        indentation += INDENTATION;
-        String name = getVarName();
-        printIndentation().append("int ").append(name).append("=");
-        genExpression(TYPE_INT);
-        sb.append(";\n");
-        addVariable(name, TYPE_INT);
-        printIndentation().append("while(").append(name).append("<");
-        genExpression(TYPE_INT);
-        sb.append(") {\n");
-        indentation += INDENTATION;
-        depth--;
-        loopDepth++;
-        printIndentation().append(name).append("=").append(name).append("+");
-        genExpression(TYPE_INT);
-        sb.append(";\n");
-        genStatements();
-        loopDepth--;
-        depth++;
-        indentation -= INDENTATION;
-        printIndentation().append("}\n");
-        indentation -= INDENTATION;
-        printIndentation().append("}");
-        popVariables(currScopeStart);
-        currScopeStart = oldCSS;
-        return 0;
-    }
-
-    /**
-     * Generate a declaration statement.
-     * @return 0
-     */
-    public int genDecl() {
-        var type = getType();
-        var name = getVarName();
-        sb.append(generateInvalid() ? getRandomName() : type.name).append(" ").append(name);
-        if (!(type instanceof TypeNullable) || random.nextBoolean()) {
-            sb.append("=");
-            genExpression(type);
-        }
-        sb.append(";");
-        addVariable(name, type);
-        return 0;
-    }
-
-    /**
-     * Generate an assignment statement.
-     * @return 0
-     */
-    public int genAssignment() {
-        Type type;
-        Type declared;
-        if (generateInvalid()) {
-            sb.append(getRandomName());
-            type = getType();
-            declared = type;
-        } else {
-            var v = findVisibleVariablesMatching(va->true);
-            if (v == null) return genDecl();
-            sb.append(v.name);
-            type = v.type;
-            declared = v.declared;
-        }
-        if (generateInvalid()) {
-            var name = getRandomName();
-            sb.append(".").append(name);
-            declared = getType();
-        } else if (type instanceof TypeStruct s && s.fields.length > 0 && random.nextBoolean()) {
-            var field = s.fields[random.nextInt(s.fields.length)];
-            sb.append(".").append(field.name);
-            declared = field.type;
-        }
-        sb.append("=");
-        genExpression(declared);
-        sb.append(";");
-        return 0;
-    }
-
-    /**
-     * Generate a return statement.
-     * @return FLAG_STOP
-     */
-    public int genReturn() {
-        var type = getType();
-        sb.append("return ");
-        genExpression(type);
-        sb.append(";");
-        return FLAG_STOP;
-    }
-
-    /**
-     * Generate a binary expression.
-     * This method does not care about operator precedence.
-     */
-    public void genExpression(Type type) {
-        if (generateInvalid()) type = getType();
-        if (type != TYPE_INT) {
-            genUnary(type);
-            return;
-        }
-        var num = randLog(MAX_BINARY_EXPRESSIONS_PER_EXPRESSION);
-        while(num-->0) {
-            genUnary(TYPE_INT);
-            sb.append(BINARY_OP[random.nextInt(BINARY_OP.length)]);
-        }
-        genUnary(TYPE_INT);
-    }
-
-    /**
-     * Generate a unary expression.
-     */
-    public void genUnary(Type type) {
-        if (generateInvalid()) type = getType();
-        if (type != TYPE_INT) {
-            genSuffix(type);
-            return;
-        }
-        var num = randLog(MAX_UNARY_EXPRESSIONS_PER_EXPRESSION);
-        while(num-->0) {
-            sb.append(UNARY_OP[random.nextInt(UNARY_OP.length)]);
-        }
-        genSuffix(TYPE_INT);
-    }
-
-    /**
-     * Generate
-     */
-    public void genSuffix(Type type) {
-        if (generateInvalid()) type = getType();
-        if (type == TYPE_INT && random.nextBoolean()) {
-            var t = getType();
-            if (generateInvalid()) {
-                var field = getRandomName();
-                genPrimary(t);
-                sb.append(".").append(field);
-                return;
-            } else if (t instanceof TypeStruct s && s.fields.length > 0) {
-                var field = s.fields[random.nextInt(s.fields.length)];
-                if (field.type == TYPE_INT) {
-                    genPrimary(t);
-                    sb.append(".").append(field.name);
-                    return;
-                }
-            }
-        }
-        genPrimary(type);
-    }
-
-    /**
-     * Generate a primary expression.
-     */
-    public void genPrimary(Type type) {
-        if (generateInvalid()) type = getType();
-        var rand = random.nextInt(10);
-        if (rand == 0 && exprDepth != 0) {
-            sb.append("(");
-            exprDepth--;
-            genExpression(type);
-            exprDepth++;
-            sb.append(")");
-        } else if (rand < 6) {
-            genVariable(type);
-        } else {
-            genConst(type);
-        }
-    }
-
-    /**
-     * Generate a constant.
-     */
-    public void genConst(Type type) {
-        if (generateInvalid()) type = getType();
-        if (type == TYPE_INT) {
-            var rand = random.nextInt(10);
-            switch (rand) {
-                case 0 -> sb.append("true");
-                case 1 -> sb.append("false");
-                default -> sb.append(random.nextInt(1<<(rand-2)));
-            }
-        } else if (type instanceof TypeNullable n) {
-            if (random.nextBoolean()) {
-                sb.append("null");
-            } else {
-                sb.append("new ").append(generateInvalid() ? getRandomName() : n.base.name);
-            }
-        } else {
-            sb.append("new ").append(generateInvalid() ? getRandomName() : type.name);
-        }
-    }
-
-    /**
-     * Generate a variable. If there are none generate a number instead.
-     * If the program is allowed to be invalid a random name can be generated in some cases.
-     */
-    public void genVariable(Type type) {
-        if (generateInvalid()) {
-            sb.append(getRandomName());
-            return;
-        }
-        if (generateInvalid()) type = getType();
-        var t = type;
-        var v = findVisibleVariablesMatching(va->va.type.isa(t));
-        if (v == null) genConst(type);
-        else sb.append(v.name);
-    }
-
-}