Chapter renumber, and split ch 17

Renumber chapters 10a, 10b, 11, 12, 13, 14 -> 10, 11, 13, 12, [11,14].
Split ch 17 into a 17a and 17b; shuffle around im/mutable syntax to be consistent, and present it more slowly.
THe new immutable syntax is pushed through all later chapters

19 files changed, 0 insertions, 4594 deletions

diff --git a/chapter10a/src/test/java/com/seaofnodes/simple/Chapter01Test.java b/chapter10a/src/test/java/com/seaofnodes/simple/Chapter01Test.java
deleted file mode 100644
index 89882b2f..00000000
--- a/chapter10a/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/chapter10a/src/test/java/com/seaofnodes/simple/Chapter02Test.java b/chapter10a/src/test/java/com/seaofnodes/simple/Chapter02Test.java
deleted file mode 100644
index a6075b75..00000000
--- a/chapter10a/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/chapter10a/src/test/java/com/seaofnodes/simple/Chapter03Test.java b/chapter10a/src/test/java/com/seaofnodes/simple/Chapter03Test.java
deleted file mode 100644
index 609dff76..00000000
--- a/chapter10a/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/chapter10a/src/test/java/com/seaofnodes/simple/Chapter04Test.java b/chapter10a/src/test/java/com/seaofnodes/simple/Chapter04Test.java
deleted file mode 100644
index edc62f50..00000000
--- a/chapter10a/src/test/java/com/seaofnodes/simple/Chapter04Test.java
+++ /dev/null
@@ -1,165 +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);
-        assertEquals(1, ((ProjNode)ret.in(1))._idx);
-        assertTrue(ret.in(2) instanceof ProjNode);
-        assertEquals(2, ((ProjNode)ret.in(2))._idx);
-    }
-
-    @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/chapter10a/src/test/java/com/seaofnodes/simple/Chapter05Test.java b/chapter10a/src/test/java/com/seaofnodes/simple/Chapter05Test.java
deleted file mode 100644
index cf7bd6cf..00000000
--- a/chapter10a/src/test/java/com/seaofnodes/simple/Chapter05Test.java
+++ /dev/null
@@ -1,228 +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(Region19,(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(Region17,4,3);", 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(Region22,2,3));", 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(Region33,(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(Region37,Phi(Region23,2,3),Phi(Region35,4,5));", 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(Region14,1,0))+Phi(Region29,2,0));", 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(Region17,3,2));", ret.toString());
-    }
-
-    @Test
-    public void testMergeSameCon() {
-        Parser parser = new Parser(
-"""
-int a=arg;
-if( arg==1 )
-    a=3;
-else
-    a=3;
-return a;
-""");
-        StopNode ret = parser.parse();
-        assertEquals("return 3;", 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/chapter10a/src/test/java/com/seaofnodes/simple/Chapter06Test.java b/chapter10a/src/test/java/com/seaofnodes/simple/Chapter06Test.java
deleted file mode 100644
index 920e26e3..00000000
--- a/chapter10a/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(Region13,2,1))<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(Region38,42,5);", 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(Region31,2,5);", 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(Region42,3,Phi(Region40,4,5));", 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(Region25,4,1);", 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(Region37,Phi(Region24,2,3),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/chapter10a/src/test/java/com/seaofnodes/simple/Chapter07Test.java b/chapter10a/src/test/java/com/seaofnodes/simple/Chapter07Test.java
deleted file mode 100644
index ff0ca599..00000000
--- a/chapter10a/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(Loop7,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(Region25,1,Phi(Loop14,1,(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(Loop9,0,Phi(Loop21,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(Loop9,2,Phi(Region28,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(Loop9,2,(Phi(Region28,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(Loop8,1,(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(Loop8,1,(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(Loop8,1,2);", 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(Loop8,1,2);", 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(Loop8,1,(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(Loop8,1,(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(Loop9,1,(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(Loop9,1,(Phi_a+3));", stop.toString());
-        assertTrue(stop.ret().ctrl() instanceof ProjNode);
-    }
-
-}
diff --git a/chapter10a/src/test/java/com/seaofnodes/simple/Chapter08Test.java b/chapter10a/src/test/java/com/seaofnodes/simple/Chapter08Test.java
deleted file mode 100644
index 4fa08bd9..00000000
--- a/chapter10a/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(Region37,Phi(Region26,Phi(Loop7,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(Loop8,1,Phi(Region43,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(Region35,Phi(Loop7,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(Region26,Phi(Loop7,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(Loop7,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(Loop7,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(Region29,Phi(Loop8,1,(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(Loop8,1,Add)+1);", stop.toString());
-        assertTrue(stop.ret().ctrl() instanceof ProjNode prj && prj._idx==1 );
-    }
-
-}
diff --git a/chapter10a/src/test/java/com/seaofnodes/simple/Chapter09Test.java b/chapter10a/src/test/java/com/seaofnodes/simple/Chapter09Test.java
deleted file mode 100644
index 1b1920e8..00000000
--- a/chapter10a/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(Loop8,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(Loop9,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(Loop15,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(Loop10,0,(-(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(Loop7,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/chapter10a/src/test/java/com/seaofnodes/simple/Chapter10Test.java b/chapter10a/src/test/java/com/seaofnodes/simple/Chapter10Test.java
deleted file mode 100644
index f39b1e78..00000000
--- a/chapter10a/src/test/java/com/seaofnodes/simple/Chapter10Test.java
+++ /dev/null
@@ -1,581 +0,0 @@
-package com.seaofnodes.simple;
-
-import com.seaofnodes.simple.node.Node;
-import com.seaofnodes.simple.node.StopNode;
-import com.seaofnodes.simple.type.*;
-import com.seaofnodes.simple.node.LoadNode;
-import com.seaofnodes.simple.node.StoreNode;
-import com.seaofnodes.simple.evaluator.Evaluator;
-import java.util.BitSet;
-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_$mem+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();
-        // The preceding len store keeps the initial x load on the bulk chain.
-        assertEquals("return Phi(Loop13,0,(Phi(Loop,.x,(Phi_x+1))+Phi_sum));", stop.toString());
-        assertEquals(10L, com.seaofnodes.simple.evaluator.Evaluator.evaluate(stop,5));
-    }
-
-
-
-
-    @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());
-    }
-
-
-    @Test public void testReadBeforeStores() {
-        var stop = new Parser("""
-            struct S { int x; int y; }
-            S a = new S; S b = new S;
-            a.x = 11; b.x = 22;
-            S p = a; if (arg) p = b;
-            int before = p.x;
-            a.y = 55; b.y = 66;
-            a.x = 33; b.x = 44;
-            return before*100 + p.x;
-            """).parse().iterate();
-        assertEquals(1133L, com.seaofnodes.simple.evaluator.Evaluator.evaluate(stop,0));
-        assertEquals(2244L, com.seaofnodes.simple.evaluator.Evaluator.evaluate(stop,1));
-    }
-
-    @Test public void testMemoryAcrossNestedLoops() {
-        var stop = new Parser("""
-            struct S { int x; int y; int z; }
-            S s = new S;
-            s.x = 5; s.y = 7; s.z = 11;
-            while (arg > 0) {
-                s.x = s.x + 1;
-                int j = 3;
-                while (j > 0) {
-                    j = j - 1;
-                    if (j == 1) continue;
-                    s.y = s.y + arg;
-                    if (arg == 2) break;
-                    s.z = s.z + 1;
-                }
-                arg = arg - 1;
-            }
-            return s;
-            """).parse().iterate();
-        for (int arg=0; arg<7; arg++) {
-            var obj = (com.seaofnodes.simple.evaluator.Evaluator.Obj)
-                com.seaofnodes.simple.evaluator.Evaluator.evaluate(stop,arg);
-            org.junit.Assert.assertArrayEquals(new Object[] {
-                5L+arg, 7L+arg*(arg+1)-(arg>=2 ? 2 : 0), 11L+2*arg-(arg>=2 ? 2 : 0)
-            }, obj.fields());
-        }
-    }
-
-    @Test public void testMemoryAtEarlyReturns() {
-        var stop = new Parser("""
-            struct S { int x; int y; int z; }
-            S s = new S;
-            s.x = 3; s.y = 5; s.z = 7;
-            if (arg) { s.x = 11; s.z = 13; return s; }
-            s.y = 17;
-            return s;
-            """).parse().iterate();
-        for (int arg=0; arg<2; arg++) {
-            var obj = (com.seaofnodes.simple.evaluator.Evaluator.Obj)
-                com.seaofnodes.simple.evaluator.Evaluator.evaluate(stop,arg);
-            org.junit.Assert.assertArrayEquals(arg==0 ? new Object[]{3L,17L,7L} : new Object[]{11L,5L,13L}, obj.fields());
-        }
-    }
-
-    @Test public void testDropLoads() {
-        StopNode stop = new Parser("""
-            struct S { int x; }
-            S a = new S; S b = new S;
-            a.x = arg; b.x = arg+1;
-            S p = a; S q = b;
-            if (arg<0) { p=b; q=a; }
-            int v;
-            if (arg>1) v=p.x; else v=q.x;
-            return v;
-            """).parse().iterate();
-        assertEquals(1,countMemoryNodes(stop,LoadNode.class,new BitSet()));
-        assertEquals(-1L,Evaluator.evaluate(stop,-1));
-        assertEquals(1L,Evaluator.evaluate(stop,0));
-        assertEquals(3L,Evaluator.evaluate(stop,3));
-    }
-
-    @Test public void testDropStores() {
-        StopNode stop = new Parser("""
-            struct S { int x; }
-            S s = new S;
-            if (arg) s.x=arg+1; else s.x=arg+2;
-            return s;
-            """).parse().iterate();
-        assertEquals(1,countMemoryNodes(stop,StoreNode.class,new BitSet()));
-        assertEquals(2L,((Evaluator.Obj)Evaluator.evaluate(stop,0)).fields()[0]);
-        assertEquals(4L,((Evaluator.Obj)Evaluator.evaluate(stop,3)).fields()[0]);
-    }
-
-    @Test public void testKeepReadsBeforeWrites() {
-        StopNode stop = new Parser("""
-            struct S { int x; int y; }
-            S a = new S; S b = new S;
-            a.x=arg; b.x=arg+1;
-            S p=a; S q=b;
-            if (arg<0) { p=b; q=a; }
-            int v;
-            if (arg>1) { v=p.x; p.x=41; p.y=5; }
-            else       { v=q.x; q.x=42; }
-            return v;
-            """).parse().iterate();
-        assertEquals(2,countMemoryNodes(stop,LoadNode.class,new BitSet()));
-        assertEquals(-1L,Evaluator.evaluate(stop,-1));
-        assertEquals(1L,Evaluator.evaluate(stop,0));
-        assertEquals(3L,Evaluator.evaluate(stop,3));
-    }
-
-    private static int countMemoryNodes(Node n, Class<?> kind, BitSet seen) {
-        if (n==null || seen.get(n._nid)) return 0;
-        seen.set(n._nid);
-        int cnt=kind.isInstance(n) ? 1 : 0;
-        for (Node def : n._inputs) cnt+=countMemoryNodes(def,kind,seen);
-        return cnt;
-    }
-}
diff --git a/chapter10a/src/test/java/com/seaofnodes/simple/FuzzerWrap.java b/chapter10a/src/test/java/com/seaofnodes/simple/FuzzerWrap.java
deleted file mode 100644
index 019140ad..00000000
--- a/chapter10a/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/chapter10a/src/test/java/com/seaofnodes/simple/SchedulerTest.java b/chapter10a/src/test/java/com/seaofnodes/simple/SchedulerTest.java
deleted file mode 100644
index ad595822..00000000
--- a/chapter10a/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/chapter10a/src/test/java/com/seaofnodes/simple/TypeTest.java b/chapter10a/src/test/java/com/seaofnodes/simple/TypeTest.java
deleted file mode 100644
index c9eb2747..00000000
--- a/chapter10a/src/test/java/com/seaofnodes/simple/TypeTest.java
+++ /dev/null
@@ -1,132 +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());
-
-        assertEquals(TypeStruct.BOT, s1.meet(s2));
-        assertEquals(TypeMem.BOT, TypeMem.TOP.meet(TypeMem.BOT));
-        assertEquals(TypeMem.TOP, TypeMem.BOT.dual());
-        assertEquals(TypeMem.BOT, TypeMem.TOP.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/chapter10a/src/test/java/com/seaofnodes/simple/evaluator/Evaluator.java b/chapter10a/src/test/java/com/seaofnodes/simple/evaluator/Evaluator.java
deleted file mode 100644
index bddcc596..00000000
--- a/chapter10a/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] = MEMORY;
-        s[2] = parameter;
-        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.expr());
-                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/chapter10a/src/test/java/com/seaofnodes/simple/evaluator/Scheduler.java b/chapter10a/src/test/java/com/seaofnodes/simple/evaluator/Scheduler.java
deleted file mode 100644
index 674d12f5..00000000
--- a/chapter10a/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/chapter10a/src/test/java/com/seaofnodes/simple/fuzzer/Fuzzer.java b/chapter10a/src/test/java/com/seaofnodes/simple/fuzzer/Fuzzer.java
deleted file mode 100644
index 7dcb88e5..00000000
--- a/chapter10a/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/chapter10a/src/test/java/com/seaofnodes/simple/fuzzer/FuzzerUtils.java b/chapter10a/src/test/java/com/seaofnodes/simple/fuzzer/FuzzerUtils.java
deleted file mode 100644
index f947a234..00000000
--- a/chapter10a/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/chapter10a/src/test/java/com/seaofnodes/simple/fuzzer/Reducer.java b/chapter10a/src/test/java/com/seaofnodes/simple/fuzzer/Reducer.java
deleted file mode 100644
index 3731b40c..00000000
--- a/chapter10a/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/chapter10a/src/test/java/com/seaofnodes/simple/fuzzer/ScriptGenerator.java b/chapter10a/src/test/java/com/seaofnodes/simple/fuzzer/ScriptGenerator.java
deleted file mode 100644
index 155063ab..00000000
--- a/chapter10a/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);
-    }
-
-}