Add shared graph viewer to all chapters

36 files changed, 181 insertions, 402 deletions

diff --git a/chapter14/src/main/java/com/seaofnodes/simple/GraphVisualizer.java b/chapter14/src/main/java/com/seaofnodes/simple/GraphVisualizer.java
deleted file mode 100644
index 604770a4..00000000
--- a/chapter14/src/main/java/com/seaofnodes/simple/GraphVisualizer.java
+++ /dev/null
@@ -1,280 +0,0 @@
-package com.seaofnodes.simple;
-
-import com.seaofnodes.simple.Parser;
-import com.seaofnodes.simple.node.*;
-
-import java.util.*;
-
-/**
- * Simple visualizer that outputs GraphViz dot format.
- * The dot output must be saved to a file and run manually via dot to generate the SVG output.
- * Currently, this is done manually.
- */
-public class GraphVisualizer {
-
-    /**
-     * If set to true we put the control nodes in a separate cluster from
-     * data nodes.
-     */
-    boolean _separateControlCluster = false;
-
-    public GraphVisualizer(boolean separateControlCluster) { this._separateControlCluster = separateControlCluster; }
-    public GraphVisualizer() { this(false); }
-
-    public String generateDotOutput(Parser parse) { return generateDotOutput(parse.STOP,parse._scope,parse._xScopes); }
-    public String generateDotOutput(StopNode stop, Node scope, Stack<ScopeNode> xScopes) {
-
-        // Since the graph has cycles, we need to create a flat list of all the
-        // nodes in the graph.
-        Collection<Node> all = findAll(stop, scope);
-        StringBuilder sb = new StringBuilder();
-        sb.append("digraph chapter11 {\n");
-        sb.append("/*\n");
-        sb.append(stop._src);
-        sb.append("\n*/\n");
-
-        // To keep the Scopes below the graph and pointing up into the graph we
-        // need to group the Nodes in a subgraph cluster, and the scopes into a
-        // different subgraph cluster.  THEN we can draw edges between the
-        // scopes and nodes.  If we try to cross subgraph cluster borders while
-        // still making the subgraphs DOT gets confused.
-        sb.append("\trankdir=BT;\n"); // Force Nodes before Scopes
-
-        // CNC - turned off Apr/8/2024, gives more flex in the layout and
-        // removes some of the more ludicrous layout choices.
-        // Preserve node input order
-        //sb.append("\tordering=\"in\";\n");
-
-        // Merge multiple edges hitting the same node.  Makes common shared
-        // nodes much prettier to look at.
-        sb.append("\tconcentrate=\"true\";\n");
-
-        // Force nested scopes to order
-        sb.append("\tcompound=\"true\";\n");
-
-        // Just the Nodes first, in a cluster no edges
-        nodes(sb, all);
-
-        // Now the scopes, in a cluster no edges
-        if( xScopes != null )
-            for( ScopeNode xscope : xScopes )
-                if( !xscope.isDead() )
-                    scope( sb, xscope );
-
-        // Walk the Node edges
-        nodeEdges(sb, all);
-
-        // Walk the active Scope edges
-        if( xScopes != null )
-            for( ScopeNode xscope : xScopes )
-                if( !xscope.isDead() )
-                    scopeEdges( sb, xscope );
-
-        sb.append("}\n");
-        return sb.toString();
-    }
-
-    private void nodesByCluster(StringBuilder sb, boolean doCtrl, Collection<Node> all) {
-        if (!_separateControlCluster && doCtrl) // all nodes in 1 cluster
-            return;
-        // Just the Nodes first, in a cluster no edges
-        sb.append(doCtrl ? "\tsubgraph cluster_Controls {\n" : "\tsubgraph cluster_Nodes {\n"); // Magic "cluster_" in the subgraph name
-        for (Node n : all) {
-            if (n instanceof ProjNode || n instanceof CProjNode || n instanceof ScopeNode || n==Parser.XCTRL)
-                continue; // Do not emit, rolled into MultiNode or Scope cluster already
-            if (_separateControlCluster && doCtrl && !n.isCFG()) continue;
-            if (_separateControlCluster && !doCtrl && n.isCFG()) continue;
-            sb.append("\t\t").append(n.uniqueName()).append(" [ ");
-            String lab = n.glabel();
-            if (n instanceof MultiNode) {
-                // Make a box with the MultiNode on top, and all the projections on the bottom
-                sb.append("shape=plaintext label=<\n");
-                sb.append("\t\t\t<TABLE BORDER=\"0\" CELLBORDER=\"1\" CELLSPACING=\"0\" CELLPADDING=\"4\">\n");
-                sb.append("\t\t\t<TR><TD BGCOLOR=\"yellow\">").append(lab).append("</TD></TR>\n");
-                sb.append("\t\t\t<TR>");
-                boolean doProjTable = false;
-                for (Node use : n._outputs) {
-                    if (use instanceof ProjNode proj) {
-                        if (!doProjTable) {
-                            doProjTable = true;
-                            sb.append("<TD>").append("\n");
-                            sb.append("\t\t\t\t<TABLE BORDER=\"0\" CELLBORDER=\"1\" CELLSPACING=\"0\">").append("\n");
-                            sb.append("\t\t\t\t<TR>");
-                        }
-                        sb.append("<TD PORT=\"p").append(proj._idx).append("\">").append(proj.glabel()).append("</TD>");
-                    }
-                    if (use instanceof CProjNode proj) {
-                        if (!doProjTable) {
-                            doProjTable = true;
-                            sb.append("<TD>").append("\n");
-                            sb.append("\t\t\t\t<TABLE BORDER=\"0\" CELLBORDER=\"1\" CELLSPACING=\"0\">").append("\n");
-                            sb.append("\t\t\t\t<TR>");
-                        }
-                        sb.append("<TD PORT=\"p").append(proj._idx).append("\" BGCOLOR=\"yellow\">").append(proj.glabel()).append("</TD>");
-                    }
-                }
-                if (doProjTable) {
-                    sb.append("</TR>").append("\n");
-                    sb.append("\t\t\t\t</TABLE>").append("\n");
-                    sb.append("\t\t\t</TD>");
-                }
-                sb.append("</TR>\n");
-                sb.append("\t\t\t</TABLE>>\n\t\t");
-
-            } else {
-                // control nodes have box shape
-                // other nodes are ellipses, i.e. default shape
-                if (n.isCFG()) sb.append("shape=box style=filled fillcolor=yellow ");
-                else if (n instanceof PhiNode) sb.append("style=filled fillcolor=lightyellow ");
-                sb.append("label=\"").append(lab).append("\" ");
-            }
-            sb.append("];\n");
-        }
-        if (!_separateControlCluster) {
-            // Force Region & Phis to line up
-            for (Node n : all) {
-                if (n instanceof RegionNode region) {
-                    sb.append("\t\t{ rank=same; ");
-                    sb.append(region).append(";");
-                    for (Node phi : region._outputs)
-                        if (phi instanceof PhiNode) sb.append(phi.uniqueName()).append(";");
-                    sb.append("}\n");
-                }
-            }
-        }
-        sb.append("\t}\n");     // End Node cluster
-    }
-
-    private void nodes(StringBuilder sb, Collection<Node> all) {
-        nodesByCluster(sb, true, all);
-        nodesByCluster(sb, false, all);
-    }
-
-    // Build a nested scope display, walking the _prev edge
-    private void scope( StringBuilder sb, ScopeNode scope ) {
-        sb.append("\tnode [shape=plaintext];\n");
-        int level=1;
-        for( int idx = scope._scopes.size()-1; idx>=0; idx-- ) {
-            var syms = scope._scopes.get(idx);
-            String scopeName = makeScopeName(scope, level);
-            sb.append("\tsubgraph cluster_").append(scopeName).append(" {\n"); // Magic "cluster_" in the subgraph name
-            sb.append("\t\t").append(scopeName).append(" [label=<\n");
-            sb.append("\t\t\t<TABLE BORDER=\"0\" CELLBORDER=\"1\" CELLSPACING=\"0\">\n");
-            // Add the scope level
-            int scopeLevel = scope._scopes.size()-level;
-            sb.append("\t\t\t<TR><TD BGCOLOR=\"cyan\">").append(scopeLevel).append("</TD>");
-            for(String name: syms.keySet())
-                sb.append("<TD PORT=\"").append(makePortName(scopeName, name)).append("\">").append(name).append("</TD>");
-            sb.append("</TR>\n");
-            sb.append("\t\t\t</TABLE>>];\n");
-            level++;
-        }
-        // Scope clusters nest, so the graphics shows the nested scopes, so
-        // they are not closed as they are printed; so they just keep nesting.
-        // We close them all at once here.
-        sb.append( "\t}\n".repeat( level-1 ) ); // End all Scope clusters
-    }
-
-    private String makeScopeName(ScopeNode sn, int level) { return sn.uniqueName() + "_" + level; }
-    private String makePortName(String scopeName, String varName) { return scopeName + "_" + varName; }
-
-    // Walk the node edges
-    private void nodeEdges(StringBuilder sb, Collection<Node> all) {
-        // All them edge labels
-        sb.append("\tedge [ fontname=Helvetica, fontsize=8 ];\n");
-        for( Node n : all ) {
-            // Do not display the Constant->Start edge;
-            // ProjNodes handled by Multi;
-            // ScopeNodes are done separately
-            if( n instanceof ConstantNode || n instanceof ProjNode || n instanceof CProjNode || n instanceof ScopeNode || n==Parser.XCTRL )
-                continue;
-            for( int i=0; i<n.nIns(); i++ ) {
-                Node def = n.in(i);
-                if( n instanceof PhiNode && def instanceof RegionNode ) {
-                    // Draw a dotted use->def edge from Phi to Region.
-                    sb.append('\t').append(n.uniqueName());
-                    sb.append(" -> ");
-                    sb.append(def.uniqueName());
-                    sb.append(" [style=dotted taillabel=").append(i).append("];\n");
-                } else if( def != null ) {
-                    // Most edges land here use->def
-                    sb.append('\t').append(n.uniqueName()).append(" -> ");
-                    if( def instanceof CProjNode proj ) {
-                        String mname = proj.ctrl().uniqueName();
-                        sb.append(mname).append(":p").append(proj._idx);
-                    } else if( def instanceof ProjNode proj ) {
-                        String mname = proj.in(0).uniqueName();
-                        sb.append(mname).append(":p").append(proj._idx);
-                    } else sb.append(def.uniqueName());
-                    // Number edges, so we can see how they track
-                    sb.append("[taillabel=").append(i);
-                    // The edge from New to ctrl is just for anchoring the New
-                    if ( n instanceof NewNode )
-                        sb.append(" color=green");
-                    // control edges are colored red
-                    else if( def.isCFG() )
-                        sb.append(" color=red");
-                    else if( def.isMem() )
-                        sb.append(" color=blue");
-                    // Backedges do not add a ranking constraint
-                    if( i==2 && (n instanceof PhiNode || n instanceof LoopNode) )
-                        sb.append(" constraint=false");
-                    sb.append("];\n");
-                }
-            }
-        }
-    }
-
-    // Walk the scope edges
-    private void scopeEdges( StringBuilder sb, ScopeNode scope ) {
-        sb.append("\tedge [style=dashed color=cornflowerblue];\n");
-        int level=1;
-        for( int i = scope._scopes.size()-1; i>=0; i-- ) {
-            var syms = scope._scopes.get(i);
-            String scopeName = makeScopeName(scope, level);
-            for( String name : syms.keySet() ) {
-                int idx = syms.get(name);
-                Node def = scope.in(idx);
-                while( def instanceof ScopeNode lazy )
-                    def = lazy.in(idx);
-                if( def==null ) continue;
-                sb.append("\t")
-                  .append(scopeName).append(":")
-                  .append('"').append(makePortName(scopeName, name)).append('"') // wrap port name with quotes because $ctrl is not valid unquoted
-                  .append(" -> ");
-                if( def instanceof CProjNode proj ) {
-                    String mname = proj.ctrl().uniqueName();
-                    sb.append(mname).append(":p").append(proj._idx);
-                } else sb.append(def.uniqueName());
-                sb.append(";\n");
-            }
-            level++;
-        }
-    }
-
-    /**
-     * Finds all nodes in the graph.
-     */
-    private Collection<Node> findAll(Node stop, Node scope) {
-        final HashMap<Integer, Node> all = new HashMap<>();
-        for( Node n : stop._inputs )
-            walk(all, n);
-        if( scope != null )
-            for( Node n : scope._inputs )
-                walk(all, n);
-        return all.values();
-    }
-
-    /**
-     * Walk a subgraph and populate distinct nodes in the all list.
-     */
-    private void walk(HashMap<Integer,Node> all, Node n) {
-        if(n == null ) return;
-        if (all.get(n._nid) != null) return; // Been there, done that
-        all.put(n._nid, n);
-        for (Node c : n._inputs)
-            walk(all, c);
-        for( Node c : n._outputs )
-            walk(all, c);
-    }
-}
diff --git a/chapter14/src/main/java/com/seaofnodes/simple/IterPeeps.java b/chapter14/src/main/java/com/seaofnodes/simple/IterPeeps.java
index 783fc4f1..7075d526 100644
--- a/chapter14/src/main/java/com/seaofnodes/simple/IterPeeps.java
+++ b/chapter14/src/main/java/com/seaofnodes/simple/IterPeeps.java
@@ -65,9 +65,14 @@ public abstract class IterPeeps {
         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() ) continue;
+                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
@@ -90,6 +95,7 @@ public abstract class IterPeeps {
             }
             if( n.isUnused() && !(n instanceof StopNode) )
                 n.kill();       // Just plain dead
+            if( obs != null ) obs.after(n, x, true);
         }
 
         return stop;
diff --git a/chapter14/src/main/java/com/seaofnodes/simple/Parser.java b/chapter14/src/main/java/com/seaofnodes/simple/Parser.java
index 9e4b9eb6..5d7d67da 100644
--- a/chapter14/src/main/java/com/seaofnodes/simple/Parser.java
+++ b/chapter14/src/main/java/com/seaofnodes/simple/Parser.java
@@ -1,5 +1,7 @@
 package com.seaofnodes.simple;
 
+import com.seaofnodes.graph.GraphObserver;
+
 import com.seaofnodes.simple.node.*;
 import com.seaofnodes.simple.type.*;
 
@@ -14,6 +16,12 @@ import java.util.*;
  */
 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
@@ -93,6 +101,7 @@ public class Parser {
     public static HashMap<String, Type> TYPES = new HashMap<>();
 
     public Parser(String source, TypeInteger arg) {
+        PARSER = this;
         Node.reset();
         IterPeeps.reset();
         TYPES.clear();
@@ -136,8 +145,7 @@ public class Parser {
 
     private Node ctrl(Node n) { return _scope.ctrl(n); }
 
-    public StopNode parse() { return parse(false); }
-    public StopNode parse(boolean show) {
+    public StopNode parse() {
         _xScopes.push(_scope);
         // Enter a new scope for the initial control and arguments
         _scope.push();
@@ -150,7 +158,6 @@ public class Parser {
         _xScopes.pop();
         if (!_lexer.isEOF()) throw error("Syntax error, unexpected " + _lexer.getAnyNextToken());
         STOP.peephole();
-        if( show ) showGraph();
         return STOP;
     }
 
@@ -190,7 +197,6 @@ public class Parser {
         else if (matchx("break")   ) return parseBreak();
         else if (matchx("continue")) return parseContinue();
         else if (matchx("struct")  ) return parseStruct();
-        else if (matchx("#showGraph")) return require(showGraph(),";");
         else if (matchx(";")       ) return null; // Empty statement
         // declarations of vars with struct type are handled in parseExpressionStatement due
         // to ambiguity
@@ -409,14 +415,7 @@ public class Parser {
         return ret;
     }
 
-    /**
-     * Dumps out the node graph
-     * @return {@code null}
-     */
-    Node showGraph() {
-        System.out.println(new GraphVisualizer().generateDotOutput(STOP,_scope,_xScopes));
-        return null;
-    }
+
 
     /**
      * Parses an expression statement or a declaration statement where type is a struct
diff --git a/chapter14/src/main/java/com/seaofnodes/simple/node/AddFNode.java b/chapter14/src/main/java/com/seaofnodes/simple/node/AddFNode.java
index 7d4e2910..5d0a473a 100644
--- a/chapter14/src/main/java/com/seaofnodes/simple/node/AddFNode.java
+++ b/chapter14/src/main/java/com/seaofnodes/simple/node/AddFNode.java
@@ -10,8 +10,6 @@ public class AddFNode extends Node {
 
     @Override public String label() { return "AddF"; }
 
-    @Override public String glabel() { return "+"; }
-
     @Override
     StringBuilder _print1(StringBuilder sb, BitSet visited) {
         in(1)._print0(sb.append("("), visited);
diff --git a/chapter14/src/main/java/com/seaofnodes/simple/node/AddNode.java b/chapter14/src/main/java/com/seaofnodes/simple/node/AddNode.java
index bd1a9dcd..31332722 100644
--- a/chapter14/src/main/java/com/seaofnodes/simple/node/AddNode.java
+++ b/chapter14/src/main/java/com/seaofnodes/simple/node/AddNode.java
@@ -9,8 +9,6 @@ public class AddNode extends Node {
 
     @Override public String label() { return "Add"; }
 
-    @Override public String glabel() { return "+"; }
-
     @Override
     StringBuilder _print1(StringBuilder sb, BitSet visited) {
         in(1)._print0(sb.append("("), visited);
diff --git a/chapter14/src/main/java/com/seaofnodes/simple/node/AndNode.java b/chapter14/src/main/java/com/seaofnodes/simple/node/AndNode.java
index 350859db..8afb14b1 100644
--- a/chapter14/src/main/java/com/seaofnodes/simple/node/AndNode.java
+++ b/chapter14/src/main/java/com/seaofnodes/simple/node/AndNode.java
@@ -10,8 +10,6 @@ public class AndNode extends Node {
 
     @Override public String label() { return "And"; }
 
-    @Override public String glabel() { return "&"; }
-
     @Override
     StringBuilder _print1(StringBuilder sb, BitSet visited) {
         in(1)._print0(sb.append("("), visited);
diff --git a/chapter14/src/main/java/com/seaofnodes/simple/node/BoolNode.java b/chapter14/src/main/java/com/seaofnodes/simple/node/BoolNode.java
index ae042f30..b504712f 100644
--- a/chapter14/src/main/java/com/seaofnodes/simple/node/BoolNode.java
+++ b/chapter14/src/main/java/com/seaofnodes/simple/node/BoolNode.java
@@ -22,9 +22,6 @@ abstract public class BoolNode extends Node {
     public String label() { return getClass().getSimpleName(); }
 
     @Override
-    public String glabel() { return op(); }
-
-    @Override
     StringBuilder _print1(StringBuilder sb, BitSet visited) {
         in(1)._print0(sb.append("("), visited);
         in(2)._print0(sb.append(op()), visited);
diff --git a/chapter14/src/main/java/com/seaofnodes/simple/node/DivFNode.java b/chapter14/src/main/java/com/seaofnodes/simple/node/DivFNode.java
index 36fd4524..6c0c2eb3 100644
--- a/chapter14/src/main/java/com/seaofnodes/simple/node/DivFNode.java
+++ b/chapter14/src/main/java/com/seaofnodes/simple/node/DivFNode.java
@@ -10,8 +10,6 @@ public class DivFNode extends Node {
 
     @Override public String label() { return "DivF"; }
 
-    @Override public String glabel() { return "/"; }
-
     @Override
     StringBuilder _print1(StringBuilder sb, BitSet visited) {
         in(1)._print0(sb.append("("), visited);
diff --git a/chapter14/src/main/java/com/seaofnodes/simple/node/DivNode.java b/chapter14/src/main/java/com/seaofnodes/simple/node/DivNode.java
index da9571db..fd5fd1ed 100644
--- a/chapter14/src/main/java/com/seaofnodes/simple/node/DivNode.java
+++ b/chapter14/src/main/java/com/seaofnodes/simple/node/DivNode.java
@@ -10,8 +10,6 @@ public class DivNode extends Node {
 
     @Override public String label() { return "Div"; }
 
-    @Override public String glabel() { return "//"; }
-
     @Override
     StringBuilder _print1(StringBuilder sb, BitSet visited) {
         in(1)._print0(sb.append("("), visited);
diff --git a/chapter14/src/main/java/com/seaofnodes/simple/node/LoadNode.java b/chapter14/src/main/java/com/seaofnodes/simple/node/LoadNode.java
index 78ccc8a9..2db5e469 100644
--- a/chapter14/src/main/java/com/seaofnodes/simple/node/LoadNode.java
+++ b/chapter14/src/main/java/com/seaofnodes/simple/node/LoadNode.java
@@ -23,8 +23,6 @@ public class LoadNode extends MemOpNode {
     }
 
     @Override public String  label() { return     _name; }
-    @Override public String glabel() { return "."+_name; }
-
     @Override
     StringBuilder _print1(StringBuilder sb, BitSet visited) { return sb.append(".").append(_name); }
 
diff --git a/chapter14/src/main/java/com/seaofnodes/simple/node/MinusFNode.java b/chapter14/src/main/java/com/seaofnodes/simple/node/MinusFNode.java
index 9727f58b..7cacf2c9 100644
--- a/chapter14/src/main/java/com/seaofnodes/simple/node/MinusFNode.java
+++ b/chapter14/src/main/java/com/seaofnodes/simple/node/MinusFNode.java
@@ -10,8 +10,6 @@ public class MinusFNode extends Node {
 
     @Override public String label() { return "MinusF"; }
 
-    @Override public String glabel() { return "-"; }
-
     @Override
     StringBuilder _print1(StringBuilder sb, BitSet visited) {
         in(1)._print0(sb.append("(-"), visited);
diff --git a/chapter14/src/main/java/com/seaofnodes/simple/node/MinusNode.java b/chapter14/src/main/java/com/seaofnodes/simple/node/MinusNode.java
index 8ba45d26..27b4a478 100644
--- a/chapter14/src/main/java/com/seaofnodes/simple/node/MinusNode.java
+++ b/chapter14/src/main/java/com/seaofnodes/simple/node/MinusNode.java
@@ -10,8 +10,6 @@ public class MinusNode extends Node {
 
     @Override public String label() { return "Minus"; }
 
-    @Override public String glabel() { return "-"; }
-
     @Override
     StringBuilder _print1(StringBuilder sb, BitSet visited) {
         in(1)._print0(sb.append("(-"), visited);
diff --git a/chapter14/src/main/java/com/seaofnodes/simple/node/MulFNode.java b/chapter14/src/main/java/com/seaofnodes/simple/node/MulFNode.java
index 2d44a9fb..4b753ba7 100644
--- a/chapter14/src/main/java/com/seaofnodes/simple/node/MulFNode.java
+++ b/chapter14/src/main/java/com/seaofnodes/simple/node/MulFNode.java
@@ -10,8 +10,6 @@ public class MulFNode extends Node {
 
     @Override public String label() { return "MulF"; }
 
-    @Override public String glabel() { return "*"; }
-
     @Override
     StringBuilder _print1(StringBuilder sb, BitSet visited) {
         in(1)._print0(sb.append("("), visited);
diff --git a/chapter14/src/main/java/com/seaofnodes/simple/node/MulNode.java b/chapter14/src/main/java/com/seaofnodes/simple/node/MulNode.java
index 6f679462..f521f2ce 100644
--- a/chapter14/src/main/java/com/seaofnodes/simple/node/MulNode.java
+++ b/chapter14/src/main/java/com/seaofnodes/simple/node/MulNode.java
@@ -10,8 +10,6 @@ public class MulNode extends Node {
 
     @Override public String label() { return "Mul"; }
 
-    @Override public String glabel() { return "*"; }
-
     @Override
     StringBuilder _print1(StringBuilder sb, BitSet visited) {
         in(1)._print0(sb.append("("), visited);
diff --git a/chapter14/src/main/java/com/seaofnodes/simple/node/NewNode.java b/chapter14/src/main/java/com/seaofnodes/simple/node/NewNode.java
index c00fee62..1c82d5f5 100644
--- a/chapter14/src/main/java/com/seaofnodes/simple/node/NewNode.java
+++ b/chapter14/src/main/java/com/seaofnodes/simple/node/NewNode.java
@@ -18,9 +18,6 @@ public class NewNode extends Node {
     public String label() { return "new"; }
 
     @Override
-    public String glabel() { return "new " + _ptr._obj._name; }
-
-    @Override
     StringBuilder _print1(StringBuilder sb, BitSet visited) {
         sb.append("new ");
         return sb.append(_ptr._obj.str());
diff --git a/chapter14/src/main/java/com/seaofnodes/simple/node/Node.java b/chapter14/src/main/java/com/seaofnodes/simple/node/Node.java
index 3956ed6b..d917893d 100644
--- a/chapter14/src/main/java/com/seaofnodes/simple/node/Node.java
+++ b/chapter14/src/main/java/com/seaofnodes/simple/node/Node.java
@@ -1,5 +1,7 @@
 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;
@@ -72,17 +74,11 @@ public abstract class Node implements OutNode {
     // Easy reading label for debugger, e.g. "Add" or "Region" or "EQ"
     public abstract String label();
 
-    // Unique label for graph visualization, e.g. "Add12" or "Region30" or "EQ99"
+    // Unique label for debugging, e.g. "Add12" or "Region30" or "EQ99"
     public String uniqueName() {
-        // Get rid of $ as graphviz doesn't like it
-        String label = label().replaceAll("\\$", "");
-        return label + _nid;
+        return label() + _nid;
     }
 
-    // Graphical label, e.g. "+" or "Region" or "=="
-    public String glabel() { return label(); }
-
-
     // ------------------------------------------------------------------------
 
     // Debugger Printing.
@@ -286,13 +282,14 @@ public abstract class Node implements OutNode {
      * Try to peephole at this node and return a better replacement Node.
      * Always returns some not-null Node (often this).
      */
-    public final Node peephole( ) {
-        if (_disablePeephole) {
-            _type = compute();
-            return this;        // Peephole optimizations turned off
-        }
+    public final Node peephole() {
+        if( _disablePeephole ) { _type = compute(); return this; }
+        var obs = IterPeeps.midAssert() ? null : Parser.PARSER == null ? null : Parser.PARSER._obs;
+        if( obs != null ) obs.before(this);
         Node n = peepholeOpt();
-        return n==null ? this : deadCodeElim(n.peephole()); // Cannot return null for no-progress
+        Node rez = n == null ? this : deadCodeElim(n.peephole());
+        if( obs != null ) obs.after(this, n == null ? null : rez, false);
+        return rez;
     }
 
     /**
@@ -450,6 +447,8 @@ public abstract class Node implements OutNode {
     // 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
@@ -460,6 +459,8 @@ public abstract class Node implements OutNode {
         // 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
diff --git a/chapter14/src/main/java/com/seaofnodes/simple/node/NotNode.java b/chapter14/src/main/java/com/seaofnodes/simple/node/NotNode.java
index b3c77c45..3ef5d19e 100644
--- a/chapter14/src/main/java/com/seaofnodes/simple/node/NotNode.java
+++ b/chapter14/src/main/java/com/seaofnodes/simple/node/NotNode.java
@@ -9,8 +9,6 @@ public class NotNode extends Node {
 
     @Override public String label() { return "Not"; }
 
-    @Override public String glabel() { return "!"; }
-
     @Override
     StringBuilder _print1(StringBuilder sb, BitSet visited) {
         in(1)._print0(sb.append("(!"), visited);
diff --git a/chapter14/src/main/java/com/seaofnodes/simple/node/OrNode.java b/chapter14/src/main/java/com/seaofnodes/simple/node/OrNode.java
index e18996b7..fd5be78e 100644
--- a/chapter14/src/main/java/com/seaofnodes/simple/node/OrNode.java
+++ b/chapter14/src/main/java/com/seaofnodes/simple/node/OrNode.java
@@ -10,8 +10,6 @@ public class OrNode extends Node {
 
     @Override public String label() { return "Or"; }
 
-    @Override public String glabel() { return "|"; }
-
     @Override
     StringBuilder _print1(StringBuilder sb, BitSet visited) {
         in(1)._print0(sb.append("("), visited);
diff --git a/chapter14/src/main/java/com/seaofnodes/simple/node/PhiNode.java b/chapter14/src/main/java/com/seaofnodes/simple/node/PhiNode.java
index 42f8c86e..1d4b3fba 100644
--- a/chapter14/src/main/java/com/seaofnodes/simple/node/PhiNode.java
+++ b/chapter14/src/main/java/com/seaofnodes/simple/node/PhiNode.java
@@ -18,8 +18,6 @@ public class PhiNode extends Node {
 
     @Override public String label() { return "Phi_"+_label; }
 
-    @Override public String glabel() { return "&phi;_"+_label; }
-
     @Override
     StringBuilder _print1(StringBuilder sb, BitSet visited) {
         if( !(region() instanceof RegionNode r) || r.inProgress() )
diff --git a/chapter14/src/main/java/com/seaofnodes/simple/node/RoundF32Node.java b/chapter14/src/main/java/com/seaofnodes/simple/node/RoundF32Node.java
index 44d3a587..3dd7cbf0 100644
--- a/chapter14/src/main/java/com/seaofnodes/simple/node/RoundF32Node.java
+++ b/chapter14/src/main/java/com/seaofnodes/simple/node/RoundF32Node.java
@@ -10,8 +10,6 @@ public class RoundF32Node extends Node {
 
     @Override public String label() { return "RoundF32"; }
 
-    @Override public String glabel() { return "(f32)"; }
-
     @Override
     StringBuilder _print1(StringBuilder sb, BitSet visited) {
         return in(1)._print0(sb.append("((f32)"), visited).append(")");
diff --git a/chapter14/src/main/java/com/seaofnodes/simple/node/SarNode.java b/chapter14/src/main/java/com/seaofnodes/simple/node/SarNode.java
index 881a3812..6436cd64 100644
--- a/chapter14/src/main/java/com/seaofnodes/simple/node/SarNode.java
+++ b/chapter14/src/main/java/com/seaofnodes/simple/node/SarNode.java
@@ -10,8 +10,6 @@ public class SarNode extends Node {
 
     @Override public String label() { return "Sar"; }
 
-    @Override public String glabel() { return ">>"; }
-
     @Override
     StringBuilder _print1(StringBuilder sb, BitSet visited) {
         in(1)._print0(sb.append("("), visited);
diff --git a/chapter14/src/main/java/com/seaofnodes/simple/node/ShlNode.java b/chapter14/src/main/java/com/seaofnodes/simple/node/ShlNode.java
index 605c5d86..1bed5264 100644
--- a/chapter14/src/main/java/com/seaofnodes/simple/node/ShlNode.java
+++ b/chapter14/src/main/java/com/seaofnodes/simple/node/ShlNode.java
@@ -10,8 +10,6 @@ public class ShlNode extends Node {
 
     @Override public String label() { return "Shl"; }
 
-    @Override public String glabel() { return "<<"; }
-
     @Override
     StringBuilder _print1(StringBuilder sb, BitSet visited) {
         in(1)._print0(sb.append("("), visited);
diff --git a/chapter14/src/main/java/com/seaofnodes/simple/node/ShrNode.java b/chapter14/src/main/java/com/seaofnodes/simple/node/ShrNode.java
index bed18d2b..26442c29 100644
--- a/chapter14/src/main/java/com/seaofnodes/simple/node/ShrNode.java
+++ b/chapter14/src/main/java/com/seaofnodes/simple/node/ShrNode.java
@@ -10,8 +10,6 @@ public class ShrNode extends Node {
 
     @Override public String label() { return "Shr"; }
 
-    @Override public String glabel() { return ">>>"; }
-
     @Override
     StringBuilder _print1(StringBuilder sb, BitSet visited) {
         in(1)._print0(sb.append("("), visited);
diff --git a/chapter14/src/main/java/com/seaofnodes/simple/node/StopNode.java b/chapter14/src/main/java/com/seaofnodes/simple/node/StopNode.java
index d5b00011..aed4a8e6 100644
--- a/chapter14/src/main/java/com/seaofnodes/simple/node/StopNode.java
+++ b/chapter14/src/main/java/com/seaofnodes/simple/node/StopNode.java
@@ -3,7 +3,6 @@ package com.seaofnodes.simple.node;
 import com.seaofnodes.simple.type.Type;
 import com.seaofnodes.simple.IterPeeps;
 import com.seaofnodes.simple.GlobalCodeMotion;
-import com.seaofnodes.simple.GraphVisualizer;
 
 import java.util.BitSet;
 
@@ -69,18 +68,16 @@ public class StopNode extends CFGNode {
         return addDef(node);
     }
 
-    public StopNode iterate(            ) { return IterPeeps.iterate(this).typeCheck().GCM(false); }
-    public StopNode iterate(boolean show) { return IterPeeps.iterate(this).typeCheck().GCM(show ); }
+    public StopNode iterate() { return IterPeeps.iterate(this).typeCheck().GCM(); }
     StopNode typeCheck() {
         String err = walk( Node::err );
         if( err != null ) throw new RuntimeException(err);
         return this;
     }
-    StopNode GCM(boolean show) {
+    StopNode GCM() {
         // Break infinite loops, forcing a Never-branch to exit
         GlobalCodeMotion.fixLoops(this);
-        if( show )
-            System.out.println(new GraphVisualizer().generateDotOutput(this,null,null));
+
         GlobalCodeMotion.buildCFG(this);
         return this;
     }
diff --git a/chapter14/src/main/java/com/seaofnodes/simple/node/StoreNode.java b/chapter14/src/main/java/com/seaofnodes/simple/node/StoreNode.java
index 57e8b3ad..142aebc3 100644
--- a/chapter14/src/main/java/com/seaofnodes/simple/node/StoreNode.java
+++ b/chapter14/src/main/java/com/seaofnodes/simple/node/StoreNode.java
@@ -25,7 +25,6 @@ public class StoreNode extends MemOpNode {
     }
 
     @Override public String  label() { return "." +_name+"="; }
-    @Override public String glabel() { return "." +_name+"="; }
     @Override public boolean isMem() { return true; }
 
     public Node val() { return in(3); }
diff --git a/chapter14/src/main/java/com/seaofnodes/simple/node/SubFNode.java b/chapter14/src/main/java/com/seaofnodes/simple/node/SubFNode.java
index b591718d..27bbda8d 100644
--- a/chapter14/src/main/java/com/seaofnodes/simple/node/SubFNode.java
+++ b/chapter14/src/main/java/com/seaofnodes/simple/node/SubFNode.java
@@ -10,8 +10,6 @@ public class SubFNode extends Node {
 
     @Override public String label() { return "SubF"; }
 
-    @Override public String glabel() { return "-"; }
-
     @Override
     StringBuilder _print1(StringBuilder sb, BitSet visited) {
         in(1)._print0(sb.append("("), visited);
diff --git a/chapter14/src/main/java/com/seaofnodes/simple/node/SubNode.java b/chapter14/src/main/java/com/seaofnodes/simple/node/SubNode.java
index 6d2f1711..45c4817c 100644
--- a/chapter14/src/main/java/com/seaofnodes/simple/node/SubNode.java
+++ b/chapter14/src/main/java/com/seaofnodes/simple/node/SubNode.java
@@ -11,8 +11,6 @@ public class SubNode extends Node {
 
     @Override public String label() { return "Sub"; }
 
-    @Override public String glabel() { return "-"; }
-
     @Override
     StringBuilder _print1(StringBuilder sb, BitSet visited) {
         in(1)._print0(sb.append("("), visited);
diff --git a/chapter14/src/main/java/com/seaofnodes/simple/node/ToFloatNode.java b/chapter14/src/main/java/com/seaofnodes/simple/node/ToFloatNode.java
index 1d147cf6..fde483d6 100644
--- a/chapter14/src/main/java/com/seaofnodes/simple/node/ToFloatNode.java
+++ b/chapter14/src/main/java/com/seaofnodes/simple/node/ToFloatNode.java
@@ -11,8 +11,6 @@ public class ToFloatNode extends Node {
 
     @Override public String label() { return "ToFloat"; }
 
-    @Override public String glabel() { return "(flt)"; }
-
     @Override
     StringBuilder _print1(StringBuilder sb, BitSet visited) {
         return in(1)._print0(sb.append("(flt)"), visited);
diff --git a/chapter14/src/main/java/com/seaofnodes/simple/node/XorNode.java b/chapter14/src/main/java/com/seaofnodes/simple/node/XorNode.java
index 3978f048..6b3bbec5 100644
--- a/chapter14/src/main/java/com/seaofnodes/simple/node/XorNode.java
+++ b/chapter14/src/main/java/com/seaofnodes/simple/node/XorNode.java
@@ -10,8 +10,6 @@ public class XorNode extends Node {
 
     @Override public String label() { return "Xor"; }
 
-    @Override public String glabel() { return "^"; }
-
     @Override
     StringBuilder _print1(StringBuilder sb, BitSet visited) {
         in(1)._print0(sb.append("("), visited);
diff --git a/chapter14/src/main/java/com/seaofnodes/simple/print/SimpleGraphAdapter.java b/chapter14/src/main/java/com/seaofnodes/simple/print/SimpleGraphAdapter.java
new file mode 100644
index 00000000..39f79e69
--- /dev/null
+++ b/chapter14/src/main/java/com/seaofnodes/simple/print/SimpleGraphAdapter.java
@@ -0,0 +1,62 @@
+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 14'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)
+            : n instanceof CProjNode 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 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 || n instanceof XCtrlNode ) return Role.ASSOC;
+        if( n instanceof PhiNode ) return i == 0 ? Role.ASSOC : isMem(n) ? Role.MEM : Role.DATA;
+        if( n instanceof ProjNode || n instanceof CProjNode ) 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/chapter14/src/main/java/com/seaofnodes/simple/print/SimpleGraphObserver.java b/chapter14/src/main/java/com/seaofnodes/simple/print/SimpleGraphObserver.java
new file mode 100644
index 00000000..5db8c01e
--- /dev/null
+++ b/chapter14/src/main/java/com/seaofnodes/simple/print/SimpleGraphObserver.java
@@ -0,0 +1,43 @@
+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 14'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);
+    }
+    @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 void roots(ArrayList<Node> roots) {
+        roots.add(Parser.START);
+        roots.add(_parser.STOP);
+        roots.add(_parser._scope);
+        roots.addAll(_parser._xScopes);
+        roots.add(_ret);
+    }
+}
diff --git a/chapter14/src/test/java/com/seaofnodes/simple/Chapter10Test.java b/chapter14/src/test/java/com/seaofnodes/simple/Chapter10Test.java
index 31220334..cfe677ec 100644
--- a/chapter14/src/test/java/com/seaofnodes/simple/Chapter10Test.java
+++ b/chapter14/src/test/java/com/seaofnodes/simple/Chapter10Test.java
@@ -81,7 +81,7 @@ if( (arg/13)==0 ) {
 int r = g+h;
 return p-r;
 """);
-        StopNode stop = parser.parse(false).iterate(false);
+        StopNode stop = parser.parse().iterate();
         assertEquals("return 0;", stop.toString());
     }
 
@@ -101,7 +101,7 @@ bar.a = 1;
 bar.a = 2;
 return bar.a;
 """);
-        StopNode stop = parser.parse(false).iterate();
+        StopNode stop = parser.parse().iterate();
         assertEquals("return 2;", stop.toString());
     }
 
@@ -155,7 +155,7 @@ while (arg) {
 }
 return bar.a;
 """);
-        StopNode stop = parser.parse(false).iterate();
+        StopNode stop = parser.parse().iterate();
         assertEquals("return Phi(Loop12,0,(Phi_a+2));", stop.toString());
     }
 
@@ -207,7 +207,7 @@ if (arg) bar = null;
 if( bar ) bar.a = 1;
 return bar;
 """);
-        StopNode stop = parser.parse(false).iterate();
+        StopNode stop = parser.parse().iterate();
         assertEquals("return Phi(Region31,(*void)Phi(Region19,null,new Bar),null);", stop.toString());
     }
 
@@ -223,7 +223,7 @@ if( !bar ) rez=4;
 else bar.a = 1;
 return rez;
 """);
-        StopNode stop = parser.parse(false).iterate();
+        StopNode stop = parser.parse().iterate();
         assertEquals("return Phi(Region37,4,3);", stop.toString());
     }
 
diff --git a/chapter14/src/test/java/com/seaofnodes/simple/Chapter11Test.java b/chapter14/src/test/java/com/seaofnodes/simple/Chapter11Test.java
index 4bfc25f4..58a11ba5 100644
--- a/chapter14/src/test/java/com/seaofnodes/simple/Chapter11Test.java
+++ b/chapter14/src/test/java/com/seaofnodes/simple/Chapter11Test.java
@@ -306,7 +306,7 @@ else {
         }
 }
 """);
-        StopNode stop = parser.parse().iterate(false);
+        StopNode stop = parser.parse().iterate();
         assertEquals("Stop[ return 9; return 0; return 0; return 0; ]", stop.toString());
     }
 
@@ -466,7 +466,7 @@ while (arg) {
 }
 return i;
 """);
-        StopNode stop = parser.parse().iterate(false);
+        StopNode stop = parser.parse().iterate();
         assertEquals("return .f;", stop.toString());
     }
 
@@ -486,7 +486,7 @@ while(arg) {
 }
 return arg;
 """);
-        StopNode stop = parser.parse().iterate(false);
+        StopNode stop = parser.parse().iterate();
         assertEquals("return Phi(Loop15,arg,Phi(Region37,.f,0));", stop.toString());
     }
 
@@ -504,7 +504,7 @@ if (arg) {
 }
 return v;
 """);
-        StopNode stop = parser.parse().iterate(false);
+        StopNode stop = parser.parse().iterate();
         assertEquals("return new S;", stop.toString());
     }
 
diff --git a/chapter14/src/test/java/com/seaofnodes/simple/Chapter12Test.java b/chapter14/src/test/java/com/seaofnodes/simple/Chapter12Test.java
index 61b1f490..c8802f4c 100644
--- a/chapter14/src/test/java/com/seaofnodes/simple/Chapter12Test.java
+++ b/chapter14/src/test/java/com/seaofnodes/simple/Chapter12Test.java
@@ -28,7 +28,7 @@ public class Chapter12Test {
 """
 return 3.14;
 """);
-        StopNode stop = parser.parse().iterate(false);
+        StopNode stop = parser.parse().iterate();
         assertEquals("return 3.14;", stop.toString());
         assertEquals(3.14, Evaluator.evaluate(stop,  0));
     }
@@ -39,7 +39,7 @@ return 3.14;
 """
 return 3.14;
 """);
-        StopNode stop = parser.parse().iterate(false);
+        StopNode stop = parser.parse().iterate();
         assertEquals("return 3.14;", stop.toString());
         assertEquals(3.14, Evaluator.evaluate(stop,  0));
     }
@@ -56,7 +56,7 @@ while( 1 ) {
 }
 return guess;
 """);
-        StopNode stop = parser.parse().iterate(false);
+        StopNode stop = parser.parse().iterate();
         assertEquals("return Phi(Loop9,(flt)arg,(((ToFloat/Phi_guess)+Phi_guess)/2.0));", stop.toString());
         assertEquals(3.0, Evaluator.evaluate(stop,  9));
         assertEquals(1.414213562373095, Evaluator.evaluate(stop,  2));
@@ -69,7 +69,7 @@ return guess;
 flt x = arg;
 return x+1==x;
 """);
-        StopNode stop = parser.parse().iterate(false);
+        StopNode stop = parser.parse().iterate();
         assertEquals("return ((flt)arg==(ToFloat+1.0));", stop.toString());
         assertEquals(0L, Evaluator.evaluate(stop, 1));
     }
diff --git a/chapter14/src/test/java/com/seaofnodes/simple/Chapter13Test.java b/chapter14/src/test/java/com/seaofnodes/simple/Chapter13Test.java
index 807badd5..66ed1073 100644
--- a/chapter14/src/test/java/com/seaofnodes/simple/Chapter13Test.java
+++ b/chapter14/src/test/java/com/seaofnodes/simple/Chapter13Test.java
@@ -14,7 +14,7 @@ public class Chapter13Test {
 """
 return 3.14;
 """);
-        StopNode stop = parser.parse().iterate(false);
+        StopNode stop = parser.parse().iterate();
         assertEquals("return 3.14;", stop.toString());
         assertEquals(3.14, Evaluator.evaluate(stop,  0));
     }
@@ -56,7 +56,7 @@ LLI? next = head.next;
 if( next==null ) return 1;
 return next.i;
 """);
-        StopNode stop = parser.parse().iterate(false);
+        StopNode stop = parser.parse().iterate();
         assertEquals("Stop[ return 0; return 1; return .i; ]", stop.toString());
         assertEquals(2L, Evaluator.evaluate(stop,  3));
     }
@@ -75,7 +75,7 @@ i0.f = f0;
 f0.i = i0;
 return f0.i.f.i.i;
 """);
-        StopNode stop = parser.parse().iterate(false);
+        StopNode stop = parser.parse().iterate();
         assertEquals("return 17;", stop.toString());
     }
 
@@ -87,7 +87,7 @@ struct N { N next; int i; }
 N n = new N;
 return n.next;
 """);
-        StopNode stop = parser.parse().iterate(false);
+        StopNode stop = parser.parse().iterate();
         assertEquals("return null;", stop.toString());
     }
 
@@ -100,7 +100,7 @@ N n = new N;
 n.next = new N;
 return n.next;
 """);
-        StopNode stop = parser.parse().iterate(false);
+        StopNode stop = parser.parse().iterate();
         assertEquals("return new N;", stop.toString());
     }
 
@@ -149,7 +149,7 @@ return n.i;
 """
 struct S{};
 """);
-        StopNode stop = parser.parse().iterate(false);
+        StopNode stop = parser.parse().iterate();
         assertEquals("return 0;", stop.toString());
         assertEquals(0L, Evaluator.evaluate(stop,  0));
     }
@@ -173,7 +173,7 @@ struct S1 { S2? s; }
 struct S2 { int x; }
 return new S1.s=new S2;
 """);
-        StopNode stop = parser.parse().iterate(false);
+        StopNode stop = parser.parse().iterate();
         assertEquals("return new S1;", stop.toString());
     }
 
@@ -190,7 +190,7 @@ p2.pi.i = 2;
 if (arg) p1 = new P;
 return p1.pi.i + 1;
 """);
-        try { parser.parse(false).iterate();  fail(); }
+        try { parser.parse().iterate();  fail(); }
         catch( Exception e ) {  assertEquals("Might be null accessing 'i'",e.getMessage());  }
     }
 
diff --git a/chapter14/src/test/java/com/seaofnodes/simple/Chapter14Test.java b/chapter14/src/test/java/com/seaofnodes/simple/Chapter14Test.java
index fcb7fa24..c4768fb3 100644
--- a/chapter14/src/test/java/com/seaofnodes/simple/Chapter14Test.java
+++ b/chapter14/src/test/java/com/seaofnodes/simple/Chapter14Test.java
@@ -15,7 +15,7 @@ public class Chapter14Test {
 """
 return 3.14;
 """);
-        StopNode stop = parser.parse(false).iterate();
+        StopNode stop = parser.parse().iterate();
         assertEquals("return 3.14;", stop.toString());
         assertEquals(3.14, Evaluator.evaluate(stop,  0));
     }
@@ -31,7 +31,7 @@ if( b < 0 ) c = -1;
 if( b > 2 ) c =  1;
 return c;
 """);
-        StopNode stop = parser.parse(false).iterate(false);
+        StopNode stop = parser.parse().iterate();
         assertEquals("return 99;", stop.toString());
         assertEquals(99L, Evaluator.evaluate(stop,  0));
     }
@@ -44,7 +44,7 @@ u8 b = 123;
 b = b + 456;// Truncate
 return b;
 """);
-        StopNode stop = parser.parse(false).iterate(false);
+        StopNode stop = parser.parse().iterate();
         assertEquals("return 67;", stop.toString());
         assertEquals(67L, Evaluator.evaluate(stop,  0));
     }
@@ -58,7 +58,7 @@ u8 b = 123;
 while( b ) b = b + 456;// Truncate
 return b;
 """);
-        StopNode stop = parser.parse(false).iterate(false);
+        StopNode stop = parser.parse().iterate();
         assertEquals("return Phi(Loop9,123,((Phi_b+456)&255));", stop.toString());
     }
 
@@ -71,7 +71,7 @@ b = b + 456;// Truncate
 u1 c = b;   // No more truncate needed
 return c;
 """);
-        StopNode stop = parser.parse(false).iterate(false);
+        StopNode stop = parser.parse().iterate();
         assertEquals("return 1;", stop.toString());
         assertEquals(1L, Evaluator.evaluate(stop,  0));
     }
@@ -84,7 +84,7 @@ int b = 123;
 b = b+456 & 31;                 // Precedence
 return b;
 """);
-        StopNode stop = parser.parse(false).iterate(false);
+        StopNode stop = parser.parse().iterate();
         assertEquals("return 3;", stop.toString());
         assertEquals(3L, Evaluator.evaluate(stop,  0));
     }
@@ -98,7 +98,7 @@ Foo f = new Foo;
 f.b = 123;
 return f.b;
 """);
-        StopNode stop = parser.parse(false).iterate(false);
+        StopNode stop = parser.parse().iterate();
         assertEquals("return 1;", stop.toString());
         assertEquals(1L, Evaluator.evaluate(stop,  0));
     }
@@ -110,7 +110,7 @@ return f.b;
 i8 b = 255;                     // Chopped
 return b;                       // Sign extend
 """);
-        StopNode stop = parser.parse(false).iterate(false);
+        StopNode stop = parser.parse().iterate();
         assertEquals("return -1;", stop.toString());
         assertEquals(-1L, Evaluator.evaluate(stop,  0));
     }
@@ -123,7 +123,7 @@ i8 b = arg;
 b = b + 1;// Truncate
 return b;
 """);
-        StopNode stop = parser.parse(false).iterate(false);
+        StopNode stop = parser.parse().iterate();
         assertEquals("return (((((arg<<56)>>56)+1)<<56)>>56);", stop.toString());
         assertEquals(1L, Evaluator.evaluate(stop,  0));
     }
@@ -136,7 +136,7 @@ u16 mask = (1<<16)-1;           // AND mask
 int c = 123456789 & mask;
 return c;                       //
 """);
-        StopNode stop = parser.parse(false).iterate(false);
+        StopNode stop = parser.parse().iterate();
         assertEquals("return 52501;", stop.toString());
         assertEquals(52501L, Evaluator.evaluate(stop,  0));
     }
@@ -151,7 +151,7 @@ int j = -i; // Negating Long.MIN_VALUE wraps, cannot constant fold
 if (arg) j = 1;
 return j;
 """);
-        StopNode stop = parser.parse(false).iterate();
+        StopNode stop = parser.parse().iterate();
         assertEquals("return Phi(Region28,1,(-((arg&9223372036854775807)+-9223372036854775808)));", stop.toString());
         assertEquals(-9223372036854775808L, Evaluator.evaluate(stop,  0));
         assertEquals(1L, Evaluator.evaluate(stop,  1));
@@ -163,7 +163,7 @@ return j;
 """
 return (arg >>> 1)==0;
 """);
-        StopNode stop = parser.parse(false).iterate();
+        StopNode stop = parser.parse().iterate();
         assertEquals("return (!(arg>>>1));", stop.toString());
         assertEquals(1L, Evaluator.evaluate(stop, 0));
         assertEquals(1L, Evaluator.evaluate(stop, 1));
@@ -176,7 +176,7 @@ return (arg >>> 1)==0;
 """
 return (arg | 123 ^ 456) >>> 1;
 """);
-        StopNode stop = parser.parse(false).iterate(false);
+        StopNode stop = parser.parse().iterate();
         assertEquals("return (((arg|123)^456)>>>1);", stop.toString());
         assertEquals(217L, Evaluator.evaluate(stop,  0));
     }
@@ -208,7 +208,7 @@ if (arg) i = a.i;
 else     i = b.i;
 return i;
 """);
-        StopNode stop = parser.parse(false).iterate(false);
+        StopNode stop = parser.parse().iterate();
         assertEquals("return Phi(Region31,.i,.i);", stop.toString());
         assertEquals(0L, Evaluator.evaluate(stop, 0));
     }
@@ -228,7 +228,7 @@ while (1) {
     return j+1;
 }
 """);
-        StopNode stop = parser.parse(false).iterate(false);
+        StopNode stop = parser.parse().iterate();
         assertEquals("return ((arg>>Phi(Region32,2,3))+1);", stop.toString());
         assertEquals(1L, Evaluator.evaluate(stop, 0));
         assertEquals(1L, Evaluator.evaluate(stop, 1));
@@ -247,7 +247,7 @@ else       b = f == 2.0;
 if (arg&5) b = arg == 1;
 return b;
 """);
-        StopNode stop = parser.parse(false).iterate(false);
+        StopNode stop = parser.parse().iterate();
         assertEquals("return Phi(Region37,(arg==1),((flt)arg==Phi(Region23,1.0,2.0)));", stop.toString());
         assertEquals(1L, Evaluator.evaluate(stop, 1));
         assertEquals(0L, Evaluator.evaluate(stop, 2));
@@ -263,7 +263,7 @@ if (arg&7) i=3;
 else       i=2;
 return (arg == i) == 1;
 """);
-        StopNode stop = parser.parse(false).iterate();
+        StopNode stop = parser.parse().iterate();
         assertEquals("return (arg==Phi(Region18,3,2));", stop.toString());
         assertEquals(0L, Evaluator.evaluate(stop,  0));
         assertEquals(0L, Evaluator.evaluate(stop,  1));
@@ -282,7 +282,7 @@ while (1) {
     return i + -1;
 }
 """);
-        StopNode stop = parser.parse(false).iterate();
+        StopNode stop = parser.parse().iterate();
         assertEquals("return (Phi(Region43,((arg&3)+9223372036854775804),((arg&7)+9223372036854775800))+-1);", stop.toString());
         assertEquals(0x7FFFFFFFFFFFFFF7L, Evaluator.evaluate(stop,  0));
         assertEquals(0x7FFFFFFFFFFFFFFCL, Evaluator.evaluate(stop,  1));
@@ -309,7 +309,7 @@ f32 ff32 = 3.141592653589793;  if( ff32 != 3.1415927410125732) return 5;
 
 return 0;
 """);
-        StopNode stop = parser.parse().iterate(false);
+        StopNode stop = parser.parse().iterate();
         assertEquals("return 0;", stop.toString());
         assertEquals(0L, Evaluator.evaluate(stop,  0));
     }