Chapter 16: Constructors

Co-authored-by: Tamás Hadházy <85063808+Hels15@users.noreply.github.com>
Co-authored-by: Hsiang-Ying Fu <66062782+fuhsnn@users.noreply.github.com>
Co-authored-by: tannal <tannal2409@gmail.com>
Co-authored-by: hadha <helsgithub15@gmail.com>
Co-authored-by: fuhsnn <66062782+fuhsnn@users.noreply.github.com>
Co-authored-by: Thalia Archibald <thalia@archibald.dev>
Co-authored-by: Symious <14933944+symious@users.noreply.github.com>
Co-authored-by: RobertObkircher <robert.obkircher@gmail.com>
Co-authored-by: Claude Opus 5 <noreply@anthropic.com>

13 files changed, 444 insertions, 220 deletions

diff --git a/src/test/java/com/seaofnodes/simple/Chapter10Test.java b/src/test/java/com/seaofnodes/simple/Chapter10Test.java
index a5e3a9e0..0b8be64b 100644
--- a/src/test/java/com/seaofnodes/simple/Chapter10Test.java
+++ b/src/test/java/com/seaofnodes/simple/Chapter10Test.java
@@ -1,10 +1,7 @@
 package com.seaofnodes.simple;
 
-import com.seaofnodes.simple.node.Node;
-import com.seaofnodes.simple.node.StopNode;
-import com.seaofnodes.simple.node.LoadNode;
-import com.seaofnodes.simple.node.StoreNode;
 import com.seaofnodes.simple.evaluator.Evaluator;
+import com.seaofnodes.simple.node.*;
 import java.util.BitSet;
 import org.junit.Test;
 import static org.junit.Assert.assertEquals;
@@ -29,9 +26,7 @@ public class Chapter10Test {
     private static final String NULLABLE_POINT_SOURCE = """
         struct Point { int x; };
         Point?[] points = new Point?[2];
-        Point point = new Point;
-        point.x = 42;
-        points[arg] = point;
+        points[arg] = new Point { x = 42; };
         Point? p = points[1];
         """;
 
@@ -101,10 +96,10 @@ return p-r;
 struct Bar {
     int a;
     int b;
-}
+};
 struct Foo {
     int x;
-}
+};
 Foo? foo = null;
 Bar bar = new Bar;
 bar.a = 1;
@@ -118,7 +113,7 @@ return bar.a;
     @Test
     public void testExample() {
         Parser parser = new Parser("""
-struct Vector2D { int x; int y; }
+struct Vector2D { int x; int y; };
 Vector2D v = new Vector2D;
 v.x = 1;
 if (arg)
@@ -136,7 +131,7 @@ return v;
         Parser parser = new Parser("""
 struct s0 {
     int v0;
-}
+};
 s0? v1=null;
 int v3=v1.zAicm;
 """);
@@ -147,7 +142,7 @@ int v3=v1.zAicm;
     @Test
     public void testBug2() {
         Parser parser = new Parser("""
-struct s0 { int v0; }
+struct s0 { int v0; };
 arg=0+new s0.0;
 """);
         try { parser.parse(); fail(); }
@@ -157,7 +152,7 @@ arg=0+new s0.0;
     @Test
     public void testLoop() {
         Parser parser = new Parser("""
-struct Bar { int a; }
+struct Bar { int a; };
 Bar bar = new Bar;
 while (arg) {
     bar.a = bar.a + 2;
@@ -166,13 +161,13 @@ while (arg) {
 return bar.a;
 """);
         StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Loop15,0,(Phi_a+2));", stop.toString());
+        assertEquals("return Phi(Loop17,0,(Phi_a+2));", stop.toString());
     }
 
     @Test
     public void testIf() {
         Parser parser = new Parser("""
-struct Bar { int a; }
+struct Bar { int a; };
 Bar bar = new Bar;
 if (arg) bar = null;
 bar.a = 1;
@@ -185,7 +180,7 @@ return bar.a;
     @Test
     public void testIf2() {
         Parser parser = new Parser("""
-struct Bar { int a; }
+struct Bar { int a; };
 Bar? bar = null;
 if (arg) bar = new Bar;
 bar.a = 1;
@@ -198,7 +193,7 @@ return bar.a;
     @Test
     public void testIf3() {
         Parser parser = new Parser("""
-struct Bar { int a; }
+struct Bar { int a; };
 Bar bar = null;
 if (arg) bar = null;
 bar.a = 1;
@@ -211,21 +206,21 @@ return bar.a;
     @Test
     public void testIfOrNull() {
         Parser parser = new Parser("""
-struct Bar { int a; }
+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(Region36,(*void)Phi(Region22,null,Bar),null);", stop.toString());
+        assertEquals("return Phi(Region38,(*void)Phi(Region24,null,Bar),null);", stop.toString());
     }
 
     @Test
     public void testIfOrNull2() {
         Parser parser = new Parser(
 """
-struct Bar { int a; }
+struct Bar { int a; };
 Bar? bar = new Bar;
 if (arg) bar = null;
 int rez = 3;
@@ -234,13 +229,13 @@ else bar.a = 1;
 return rez;
 """);
         StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Region42,4,3);", stop.toString());
+        assertEquals("return Phi(Region44,4,3);", stop.toString());
     }
 
     @Test
     public void testWhileWithNullInside() {
         Parser parser = new Parser("""
-struct s0 {int v0;}
+struct s0 {int v0;};
 s0? v0 = new s0;
 int ret = 0;
 while(arg) {
@@ -260,7 +255,7 @@ return ret;
         Parser parser = new Parser("""
 struct s0 {
     int v0;
-}
+};
 s0? v1=new s0;
 s0? v1;
 v1=new s0;
@@ -277,7 +272,7 @@ v1=new s0;
 struct Iter {
     int x;
     int len;
-}
+};
 Iter i = new Iter;
 i.len = arg;
 int sum=0;
@@ -288,16 +283,14 @@ while( i.x < i.len ) {
 return sum;
 """);
         StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Loop19,0,(Phi(Loop,0,(Phi_x+1))+Phi_sum));", stop.toString());
+        assertEquals("return Phi(Loop22,0,(Phi(Loop,0,(Phi_x+1))+Phi_sum));", stop.toString());
     }
 
 
-
-
     @Test
     public void test1() {
         Parser parser = new Parser("""
-struct s0 {int v0;}
+struct s0 {int v0;};
 s0 ret = new s0;
 while(arg) {
     s0 v0 = new s0;
@@ -309,13 +302,13 @@ while(arg) {
 return ret;
 """);
         StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Loop15,s0,Phi(Region42,s0,Phi_ret));", stop.toString());
+        assertEquals("return Phi(Loop17,s0,Phi(Region44,s0,Phi_ret));", stop.toString());
     }
 
     @Test
     public void test2() {
         Parser parser = new Parser("""
-struct s0 {int v0;}
+struct s0 {int v0;};
 s0 ret = new s0;
 s0 v0 = new s0;
 while(arg) {
@@ -327,14 +320,14 @@ while(arg) {
 return ret;
 """);
         StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Loop21,s0,Phi(Region43,s0,Phi_ret));", stop.toString());
+        assertEquals("return Phi(Loop23,s0,Phi(Region45,s0,Phi_ret));", stop.toString());
     }
 
 
     @Test
     public void test3() {
         Parser parser = new Parser("""
-struct s0 {int v0;}
+struct s0 {int v0;};
 s0 ret = new s0;
 while(arg < 10) {
     s0 v0 = new s0;
@@ -344,21 +337,19 @@ while(arg < 10) {
 return ret;
 """);
         StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Loop15,s0,Phi(Region39,s0,Phi_ret));", stop.toString());
+        assertEquals("return Phi(Loop17,s0,Phi(Region41,s0,Phi_ret));", stop.toString());
     }
 
     @Test
     public void testBug3() {
         Parser parser = new Parser("""
-struct s0 {
-    int f0;
-}
-if(0>=0) return new s0;
+struct s0 { int f0; };
 return new s0;
 int v0=null.f0;
 """);
-        try { parser.parse(); fail(); }
-        catch( Exception e ) { assertEquals("Accessing unknown field 'f0' from 'null'", e.getMessage()); }
+        StopNode stop = parser.parse().iterate();
+        assertEquals("return s0;", stop.toString());
+        assertEquals("Obj<s0>{f0=0}", Evaluator.evaluate(stop, 0).toString());
     }
 
     @Test
@@ -382,7 +373,7 @@ if(0) {
         Parser parser = new Parser("""
 struct s0 {
     int f0;
-}
+};
 if(0) return 0;
 else return new s0;
 if(new s0.f0) return 0;
@@ -409,7 +400,7 @@ return 0;
     @Test
     public void testBug7() {
         Parser parser = new Parser("""
-struct s0 {  int f0; }
+struct s0 {  int f0; };
 s0 v0 = new s0;
 while(v0.f0) {}
 s0 v1 = v0;
@@ -464,7 +455,7 @@ return 0;
 
     @Test public void testReadBeforeStores() {
         var stop = new Parser("""
-            struct S { int x; int y; }
+            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;
@@ -478,7 +469,7 @@ return 0;
     }
 
     static final String NESTED_MEMORY = """
-            struct S { int x; int y; int z; }
+            struct S { int x; int y; int z; };
             S s = new S;
             s.x = 5; s.y = 7; s.z = 11;
             while (arg > 0) {
@@ -509,7 +500,7 @@ return 0;
 
     @Test public void testMemoryAtEarlyReturns() {
         var stop = new Parser("""
-            struct S { int x; int y; int z; }
+            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; }
@@ -525,7 +516,7 @@ return 0;
 
     @Test public void testKeepLoadsAtMerge() {
         StopNode stop = new Parser("""
-            struct S { int x; }
+            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;
@@ -543,7 +534,7 @@ return 0;
 
     @Test public void testDropStores() {
         StopNode stop = new Parser("""
-            struct S { int x; }
+            struct S { int x; };
             S s = new S;
             if (arg) s.x=arg+1; else s.x=arg+2;
             return s;
@@ -555,7 +546,7 @@ return 0;
 
     @Test public void testKeepReadsBeforeWrites() {
         StopNode stop = new Parser("""
-            struct S { int x; int y; }
+            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;
diff --git a/src/test/java/com/seaofnodes/simple/Chapter11Test.java b/src/test/java/com/seaofnodes/simple/Chapter11Test.java
index 5f92c9c1..e009c6b6 100644
--- a/src/test/java/com/seaofnodes/simple/Chapter11Test.java
+++ b/src/test/java/com/seaofnodes/simple/Chapter11Test.java
@@ -8,7 +8,7 @@ import static org.junit.Assert.*;
 public class Chapter11Test {
     @Test public void testIndependentField() {
         var stop = new Parser("""
-            struct S { int x; int y; }
+            struct S { int x; int y; };
             S s = new S;
             s.x = 42;
             while (arg > 0) { s.y = s.y + arg; arg = arg - 1; }
@@ -21,7 +21,7 @@ public class Chapter11Test {
 
     @Test public void testParallelMemoryPhis() {
         var stop = new Parser("""
-            struct S { int x; int y; int z; }
+            struct S { int x; int y; int z; };
             S a = new S; S b = new S;
             S p = a; if (arg) p = b;
             while (arg > 0) {
diff --git a/src/test/java/com/seaofnodes/simple/Chapter12Test.java b/src/test/java/com/seaofnodes/simple/Chapter12Test.java
index e885deb3..22976058 100644
--- a/src/test/java/com/seaofnodes/simple/Chapter12Test.java
+++ b/src/test/java/com/seaofnodes/simple/Chapter12Test.java
@@ -2,7 +2,6 @@ package com.seaofnodes.simple;
 
 import com.seaofnodes.simple.evaluator.Evaluator;
 import com.seaofnodes.simple.node.StopNode;
-import org.junit.Ignore;
 import org.junit.Test;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.fail;
@@ -23,7 +22,7 @@ return 3.14;
     public void testLinkedList0() {
         Parser parser = new Parser(
 """
-struct LLI { LLI? next; int i; }
+struct LLI { LLI? next; int i; };
 LLI? head = null;
 while( arg ) {
     LLI x = new LLI;
@@ -42,7 +41,7 @@ return head.next.i;
     public void testLinkedList1() {
         Parser parser = new Parser(
 """
-struct LLI { LLI? next; int i; }
+struct LLI { LLI? next; int i; };
 LLI? head = null;
 while( arg ) {
     LLI x = new LLI;
@@ -65,8 +64,8 @@ return next.i;
     public void testCoRecur() {
         Parser parser = new Parser(
 """
-struct int0 { int i; flt0? f; }
-struct flt0 { flt f; int0? i; }
+struct int0 { int i; flt0? f; };
+struct flt0 { flt f; int0? i; };
 int0 i0 = new int0;
 i0.i = 17;
 flt0 f0 = new flt0;
@@ -83,7 +82,7 @@ return f0.i.f.i.i;
     public void testNullRef0() {
         Parser parser = new Parser(
 """
-struct N { N next; int i; }
+struct N { N? next; int i; };
 N n = new N;
 return n.next;
 """);
@@ -95,33 +94,33 @@ return n.next;
     public void testNullRef1() {
         Parser parser = new Parser(
 """
-struct N { N next; int i; }
-N n = new N;
-n.next = new N;
+struct M { int m; };
+struct N { M next; int i; };
+N n = new N { next = new M; };
 return n.next;
 """);
         StopNode stop = parser.parse().iterate();
-        assertEquals("return N;", stop.toString());
+        assertEquals("return M;", stop.toString());
     }
 
     @Test
     public void testNullRef2() {
         Parser parser = new Parser(
 """
-struct N { N next; int i; }
-N n = new N;
-n.next = null;
+struct M { int m; };
+struct N { M next; int i; };
+N n = new N { next = null; }
 return n.next;
 """);
         try { parser.parse().iterate(); fail(); }
-        catch( Exception e ) { assertEquals("Cannot store null into field *N next",e.getMessage()); }
+        catch( Exception e ) { assertEquals("Type null is not of declared type *M",e.getMessage()); }
     }
 
     @Test
     public void testNullRef3() {
         Parser parser = new Parser(
 """
-struct N { N next; int i; }
+struct N { N? next; int i; };
 N n = new N;
 n.i = 3.14;
 return n.i;
@@ -158,7 +157,7 @@ struct S{};
     public void testForwardRef0() {
         Parser parser = new Parser(
 """
-struct S1 { S2 s; }
+struct S1 { S2 s; };
 return new S2;
 """);
         try { parser.parse().iterate(); fail(); }
@@ -169,8 +168,8 @@ return new S2;
     public void testForwardRef1() {
         Parser parser = new Parser(
 """
-struct S1 { S2? s; }
-struct S2 { int x; }
+struct S1 { S2? s; };
+struct S2 { int x; };
 return new S1.s=new S2;
 """);
         StopNode stop = parser.parse().iterate();
@@ -181,8 +180,8 @@ return new S1.s=new S2;
     public void testcheckNull() {
         Parser parser = new Parser(
 """
-struct I {int i;}
-struct P {I pi;}
+struct I {int i;};
+struct P { I? pi; };
 P p1 = new P;
 P p2 = new P;
 p2.pi = new I;
diff --git a/src/test/java/com/seaofnodes/simple/Chapter13Test.java b/src/test/java/com/seaofnodes/simple/Chapter13Test.java
index 3373a1aa..c749aba6 100644
--- a/src/test/java/com/seaofnodes/simple/Chapter13Test.java
+++ b/src/test/java/com/seaofnodes/simple/Chapter13Test.java
@@ -293,7 +293,7 @@ else {
 }
 """);
         StopNode stop = parser.parse().iterate();
-        assertEquals("Stop[ return 9; return 0; return 0; return 0; ]", stop.toString());
+        assertEquals("Stop[ return 9; return 0; return 0; ]", stop.toString());
     }
 
 
@@ -338,7 +338,7 @@ return primeCount;
     public void testAntiDeps1() {
         Parser parser = new Parser(
 """
-struct S { int f; }
+struct S { int f; };
 S v=new S;
 v.f = 2;
 int i=new S.f;
@@ -356,7 +356,7 @@ return i;
     public void testAntiDeps2() {
         Parser parser = new Parser(
 """
-struct S { int f; }
+struct S { int f; };
 S v = new S;
 v.f = arg;
 S t = new S;
@@ -370,14 +370,14 @@ if (arg) {
 return i;
 """);
         StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Region46,.f,0);", stop.toString());
+        assertEquals("return Phi(Region48,.f,0);", stop.toString());
     }
 
     @Test
     public void testAntiDeps3() {
         Parser parser = new Parser(
 """
-struct S { int f; }
+struct S { int f; };
 S v0 = new S;
 S? v1;
 if (arg) v1 = new S;
@@ -397,7 +397,7 @@ return v0;
     public void testAntiDeps4() {
         Parser parser = new Parser(
 """
-struct S { int f; }
+struct S { int f; };
 S v = new S;
 v.f = arg;
 S t = new S;
@@ -414,7 +414,7 @@ return i;
     public void testAntiDeps5() {
         Parser parser = new Parser(
 """
-struct S { int f; }
+struct S { int f; };
 S v = new S;
 while(1) {
     while(arg+1) { arg=arg-1; }
@@ -431,7 +431,7 @@ return v;
     public void testAntiDeps6() {
         Parser parser = new Parser(
 """
-struct s { int v; }
+struct s { int v; };
 s ptr=new s;
 while( -arg )
   ptr = new s;
@@ -446,7 +446,7 @@ while(1)
     public void testAntiDeps7() {
         Parser parser = new Parser(
 """
-struct S { int f; }
+struct S { int f; };
 S v = new S;
 S t = new S;
 int i = v.f;
@@ -464,7 +464,7 @@ return i;
     public void testAntiDeps8() {
         Parser parser = new Parser(
 """
-struct S { int f; }
+struct S { int f; };
 S v = new S;
 S t = new S;
 while(arg) {
@@ -477,14 +477,14 @@ while(arg) {
 return arg;
 """);
         StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Loop21,arg,Phi(Region48,.f,0));", stop.toString());
+        assertEquals("return Phi(Loop23,arg,Phi(Region50,.f,0));", stop.toString());
     }
 
     @Test
     public void testAntiDeps9() {
         Parser parser = new Parser(
 """
-struct S { int f; }
+struct S { int f; };
 S v = new S;
 S t = new S;
 if (arg) {
@@ -501,8 +501,8 @@ return v;
     @Test
     public void testExample2() {
         Parser parser = new Parser(
-                """
-struct S { int f; }
+"""
+struct S { int f; };
 S v = new S;
 int i = arg;
 while (arg > 0) {
@@ -516,4 +516,39 @@ return v;
         StopNode stop = parser.parse().iterate();
         //assertEquals("return new S;", stop.toString());
     }
+
+    @Test
+    public void testScheduleUse() {
+        Parser parser = new Parser(
+"""
+int v0=0;
+while(0>=0) {
+    u1 v1=0;
+    v1=v0;
+    if(v1*0)
+        v0=-v1;
+}
+return 0;
+""");
+        StopNode stop = parser.parse().iterate();
+        assertEquals("return 0;", stop.toString());
+    }
+
+    @Test
+    public void testLoopCarriedDep() {
+        Parser parser = new Parser(
+"""
+u32 v0=0;
+{
+    int v1=0;
+    while(v1) {
+        v1=1>>>v0!=0;
+        v0=v1/0;
+    }
+}
+""");
+        StopNode stop = parser.parse().iterate();
+        assertEquals("return 0;", stop.toString());
+    }
+
 }
diff --git a/src/test/java/com/seaofnodes/simple/Chapter14Test.java b/src/test/java/com/seaofnodes/simple/Chapter14Test.java
index d64423de..03a02795 100644
--- a/src/test/java/com/seaofnodes/simple/Chapter14Test.java
+++ b/src/test/java/com/seaofnodes/simple/Chapter14Test.java
@@ -93,7 +93,7 @@ return b;
     public void testRefLoad() {
         Parser parser = new Parser(
 """
-struct Foo { u1 b; }
+struct Foo { u1 b; };
 Foo f = new Foo;
 f.b = 123;
 return f.b;
@@ -166,6 +166,39 @@ return arg;
     }
 
     @Test
+    public void testCloneAnd() {
+        Parser parser = new Parser("""
+int v0=0;
+u32 v1 = 1&(1<<arg)&(1<<arg);
+while(arg) v1=-v0;
+while(v1) break;
+return v1;
+""");
+        StopNode stop = parser.parse().iterate();
+        assertEquals("return (Phi(Loop17,((1<<arg)&1),0)&Phi(Loop,Shl,4294967295));", stop.toString());
+        assertEquals(1L, Evaluator.evaluate(stop,  0));
+    }
+
+    @Test
+    public void testAndHigh() {
+        Parser parser = new Parser("""
+int v0=0;
+if(0&0>>>0) {
+    while(0) {
+        u8 v1=0;
+        v0=0>>>0;
+        v1=arg;
+        while(v1+0) {}
+    }
+}
+return v0;
+""");
+        StopNode stop = parser.parse().iterate();
+        assertEquals("return 0;", stop.toString());
+        assertEquals(0L, Evaluator.evaluate(stop,  0));
+    }
+
+    @Test
     public void testTypes() {
         Parser parser = new Parser(
 """
diff --git a/src/test/java/com/seaofnodes/simple/Chapter15Test.java b/src/test/java/com/seaofnodes/simple/Chapter15Test.java
index 8f9d2d14..643b45e7 100644
--- a/src/test/java/com/seaofnodes/simple/Chapter15Test.java
+++ b/src/test/java/com/seaofnodes/simple/Chapter15Test.java
@@ -4,81 +4,15 @@ import com.seaofnodes.simple.evaluator.Evaluator;
 import com.seaofnodes.simple.node.StopNode;
 import org.junit.Test;
 import org.junit.Ignore;
-
-import java.nio.charset.StandardCharsets;
-
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.fail;
 
 public class Chapter15Test {
 
-    @Test public void testPartialAllocationMemory() {
-        StopNode stop = new Parser("""
-            struct Other { int a; int b; int c; }
-            struct S { int x; flt y; S? next; }
-            Other other = new Other;
-            other.c = 7;
-            S a = new S;
-            a.x = arg;
-            a.y = 1.5;
-            S b = new S;
-            // S's aliases are global identities, not tuple or input positions.
-            // Bypass b's zeroing for a, preserving the unrelated Other slice.
-            return a.x + a.y + b.x + b.y + other.c;
-            """).parse().iterate();
-        assertEquals(8.5, Evaluator.evaluate(stop,0));
-        assertEquals(12.5, Evaluator.evaluate(stop,4));
-
-        stop = new Parser("""
-            struct S { int x; flt y; S? next; }
-            S a = new S; S b = new S;
-            S p = a; if (arg) p = b;
-            // The memory result carries distinct int, float and pointer facts.
-            if (p.next != null) return 99;
-            return p.x + p.y;
-            """).parse().iterate();
-        assertEquals("return 0.0;",stop.toString());
-        assertEquals(0.0,Evaluator.evaluate(stop,1));
-    }
-
-    @Test public void testReadAcrossAllocation() {
-        StopNode stop = new Parser("""
-            struct S { int x; }
-            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;
-            S c = new S;
-            a.x = 33; b.x = 44;
-            // The partial input to c must not hide the read/write ordering.
-            // p can alias either object, so node inequality cannot bypass New.
-            return before*100 + p.x + c.x;
-            """).parse().iterate();
-        assertEquals(1133L,Evaluator.evaluate(stop,0));
-        assertEquals(2244L,Evaluator.evaluate(stop,1));
-    }
-
-    @Test public void testAllocationInLoop() {
-        StopNode stop = new Parser("""
-            struct S { int x; flt y; S? next; }
-            S old = new S; old.x = 7;
-            S last = old;
-            while (arg > 0) {
-                S fresh = new S;
-                fresh.x = last.x + 1;
-                fresh.next = last;
-                last = fresh;
-                arg = arg - 1;
-            }
-            return old.x*100 + last.x;
-            """).parse().iterate();
-        assertEquals(707L,Evaluator.evaluate(stop,0));
-        assertEquals(712L,Evaluator.evaluate(stop,5));
-    }
-
     @Test
     public void testJig() {
-        Parser parser = new Parser("""
+        Parser parser = new Parser(
+"""
 return 3.14;
 """);
         StopNode stop = parser.parse().iterate();
@@ -87,29 +21,10 @@ return 3.14;
     }
 
     @Test
-    public void testLifetime() {
-        Parser parser = new Parser("""
-u8[] b = new u8[5];
-if (arg) {
-    b[0] = b[0] + 1;
-} else {
-    b[1] = b[1] * 2;
-}
-return b[0] + b[1];
-""");
-        StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Region72,1,0);", stop.toString());
-        assertEquals(0L, Evaluator.evaluate(stop,  0));
-        assertEquals(1L, Evaluator.evaluate(stop,  1));
-    }
-
-    @Test
     public void testCyclic() {
         Parser parser = new Parser(
 """
-struct C {
-    C? l;
-}
+struct C { C? l; };
 C c = new C;
 c.l = c;
 return c;
@@ -134,7 +49,7 @@ output[i] = 1;
 return output;
 """);
         StopNode stop = parser.parse().iterate();
-        assertEquals("return u8[];", stop.toString());
+        assertEquals("return [u8];", stop.toString());
         assertEquals("\u0001", Evaluator.evaluate(stop,  0).toString());
     }
 
@@ -181,20 +96,20 @@ return a[0];
     public void testBasic4() {
         Parser parser = new Parser(
 """
-struct A { int i; }
+struct A { int i; };
 A?[] a = new A?[2];
 return a;
 """);
         StopNode stop = parser.parse().iterate();
-        assertEquals("return *A?[];", stop.toString());
-        assertEquals("Obj<*A?[]>{#=2,[]=[null,null]}", Evaluator.evaluate(stop, 0).toString());
+        assertEquals("return [*A?];", stop.toString());
+        assertEquals("Obj<[*A?]>{#=2,[]=[null,null]}", Evaluator.evaluate(stop, 0).toString());
     }
 
     @Test
     public void testBasic5() {
         Parser parser = new Parser(
 """
-struct S { int x; flt y; }
+struct S { int x; flt y; };
 // A new S
 S s = new S; s.x=99; s.y = 3.14;
 
@@ -215,8 +130,10 @@ else {
 return rez;
 """);
         StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Region122,1.2,Phi(Region119,2.3,.y));", stop.toString());
+        // Shared allocation memory prevents folding the field Store into New.
+        assertEquals("return Phi(Region121,1.2,Phi(Region118,2.3,.y));", stop.toString());
         assertEquals(3.14, Evaluator.evaluate(stop, 0));
+        assertEquals(1.2 , Evaluator.evaluate(stop, 1));
     }
 
     @Ignore
@@ -224,7 +141,7 @@ return rez;
     public void testBasic6() {
         Parser parser = new Parser(
 """
-struct S { int x; flt y; }
+struct S { int x; flt y; };
 // A new S
 S s = new S; s.x=99; s.y = 3.14;
 
@@ -250,7 +167,7 @@ return rez;
         Parser parser = new Parser(
 """
 // Can we define a forward-reference array?
-struct Tree { Tree?[] _kids; }
+struct Tree { Tree?[]? _kids; };
 Tree root = new Tree;
 root._kids = new Tree?[2];
 root._kids[0] = new Tree;
@@ -258,17 +175,14 @@ return root;
 """);
         StopNode stop = parser.parse().iterate();
         assertEquals("return Tree;", stop.toString());
-        assertEquals("Obj<Tree>{_kids=Obj<*Tree?[]>{#=2,[]=[Obj<Tree>{_kids=null},null]}}", Evaluator.evaluate(stop,  0).toString());
+        assertEquals("Obj<Tree>{_kids=Obj<[*Tree?]>{#=2,[]=[Obj<Tree>{_kids=null},null]}}", Evaluator.evaluate(stop,  0).toString());
     }
 
     @Test
     public void testNestedStructAddMemProj() {
         Parser parser = new Parser(
 """
-struct S {
-    int a;
-    int[] b;
-}
+struct S { int a; int[] b; };
 return 0;
 """);
         StopNode stop = parser.parse();
@@ -338,9 +252,9 @@ while( j < nprimes ) {
 return rez;
 """);
         StopNode stop = parser.parse().iterate();
-        assertEquals("return int[];", stop.toString());
+        assertEquals("return [int];", stop.toString());
         Evaluator.Obj obj = (Evaluator.Obj)Evaluator.evaluate(stop, 20);
-        assertEquals("int[] {\n  # :int;\n  [] :int;\n}",obj.struct().toString());
+        assertEquals("[int] {  # :int;   [] :int; }",obj.struct().toString());
         long nprimes = (Long)obj.fields()[0];
         long[] primes = new long[]{2,3,5,7,11,13,17,19};
         for( int i=0; i<nprimes; i++ )
@@ -351,7 +265,7 @@ return rez;
     public void testNewNodeInit() {
         Parser parser = new Parser(
 """
-struct S {int i; flt f;}
+struct S {int i; flt f;};
 S s1 = new S;
 S s2 = new S;
 s2.i = 3;
@@ -382,7 +296,7 @@ return new flt;
 int is = new int[2];
 """);
         try { parser.parse().iterate(); fail(); }
-        catch( Exception e ) { assertEquals("Type *int[] is not of declared type int",e.getMessage()); }
+        catch( Exception e ) { assertEquals("Type *[int] is not of declared type int",e.getMessage()); }
     }
 
     @Test
@@ -412,4 +326,67 @@ return is[1];
         catch( NegativeArraySizeException e ) { assertEquals("-1",e.getMessage()); }
     }
 
+    @Test
+    public void testProgress() {
+        Parser parser = new Parser("""
+i8 v1=0&0;
+u8 v2=0;
+byte v4=0;
+if(0) {}
+while(v2<0) {
+    v4=0-v1;
+    break;
+}
+int v5=0&0;
+while(v5+(0&0)) {
+    int v7=0&0;
+    while(v7)
+        v4=0>>>v5;
+    while(v1)
+        return 0;
+}
+return v1;
+""");
+        StopNode stop = parser.parse().iterate();
+        assertEquals("return 0;", stop.toString());
+        assertEquals(0L, Evaluator.evaluate(stop,  0));
+    }
+
+    @Test
+    public void testSharpNot() {
+        Parser parser = new Parser(
+"""
+if(0>>0) {}
+while(0) {}
+u32 v7=0;
+int v8=0;
+while(0<--1>>>---(v7*0==v8)) {}
+""");
+        StopNode stop = parser.parse().iterate();
+        assertEquals("return 0;", stop.toString());
+    }
+
+
+    @Test
+    public void testProgress2() {
+        Parser parser = new Parser(
+"""
+if(1) {}
+else {
+        while(arg>>>0&0>>>0) {}
+    byte v3=0>>>0;
+                while(0) {}
+        int v7=0>>>0;
+        while(v7<0>>>0) {
+                    while(0+v7<=0) if(1) arg=-12;
+            if(arg) {
+                v3=arg+v3+0;
+                arg=0;
+            }
+        }
+}
+""");
+        StopNode stop = parser.parse().iterate();
+        assertEquals("return 0;", stop.toString());
+    }
 }
diff --git a/src/test/java/com/seaofnodes/simple/Chapter16Test.java b/src/test/java/com/seaofnodes/simple/Chapter16Test.java
new file mode 100644
index 00000000..0f5a5a16
--- /dev/null
+++ b/src/test/java/com/seaofnodes/simple/Chapter16Test.java
@@ -0,0 +1,189 @@
+package com.seaofnodes.simple;
+
+import com.seaofnodes.simple.evaluator.Evaluator;
+import com.seaofnodes.simple.node.StopNode;
+import org.junit.Test;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.fail;
+
+public class Chapter16Test {
+
+    @Test
+    public void testRequiredReference() {
+        for( String fields : new String[] { "int[] x;" } ) {
+            String src = "struct Point { "+fields+" }; Point p = new Point; p.x=p.x+1; return p;";
+            try { new Parser(src).parse().iterate(); fail(fields); }
+            catch( Exception e ) { assertEquals("'Point' is not fully initialized, field 'x' needs to be set in a constructor",e.getMessage()); }
+        }
+    }
+
+    @Test
+    public void testJig() {
+        Parser parser = new Parser(
+"""
+return 3.14;
+""");
+        StopNode stop = parser.parse().iterate();
+        assertEquals("return 3.14;", stop.toString());
+        assertEquals(3.14, Evaluator.evaluate(stop,  0));
+    }
+
+
+    @Test
+    public void testMulti0() {
+        Parser parser = new Parser(
+"""
+int x, y;
+return x+y;
+""");
+        StopNode stop = parser.parse().iterate();
+        assertEquals("return 0;", stop.toString());
+        assertEquals(0L, Evaluator.evaluate(stop,  0));
+    }
+    @Test
+    public void testMulti1() {
+        Parser parser = new Parser(
+"""
+int x=2, y=x+1;
+return x+y;
+""");
+        StopNode stop = parser.parse().iterate();
+        assertEquals("return 5;", stop.toString());
+        assertEquals(5L, Evaluator.evaluate(stop,  0));
+    }
+
+
+
+
+
+    @Test
+    public void testConstruct0() {
+        Parser parser = new Parser("""
+struct X { int x=3; };
+X z = new X;
+return z.x;
+""");
+        StopNode stop = parser.parse().iterate();
+        assertEquals("return 3;", stop.toString());
+        assertEquals(3L, Evaluator.evaluate(stop,  0));
+    }
+
+
+
+    @Test
+    public void testConstruct2() {
+        Parser parser = new Parser("""
+struct X { int x=3; };
+X z = new X { x = 4; };
+return z.x;
+""");
+        StopNode stop = parser.parse().iterate();
+        assertEquals("return 4;", stop.toString());
+        assertEquals(4L, Evaluator.evaluate(stop,  0));
+    }
+
+
+
+
+    // Same as the Chapter13 test with the same name, but using the new
+    // constructor syntax
+    @Test
+    public void testLinkedList1() {
+        Parser parser = new Parser(
+"""
+struct LLI { LLI? next; int i; };
+LLI? head = null;
+while( arg ) {
+    head = new LLI { next=head; i=arg; };
+    arg = arg-1;
+}
+if( !head ) return 0;
+LLI? next = head.next;
+if( !next ) return 1;
+return next.i;
+""");
+        StopNode stop = parser.parse().iterate();
+        assertEquals("Stop[ return 0; return 1; return .i; ]", stop.toString());
+        assertEquals(0L, Evaluator.evaluate(stop,  0));
+        assertEquals(1L, Evaluator.evaluate(stop,  1));
+        assertEquals(2L, Evaluator.evaluate(stop,  3));
+    }
+
+    @Test
+    public void testLinkedList2() {
+        Parser parser = new Parser(
+"""
+struct LLI { LLI? next; int i; };
+LLI? head = null;
+while( arg ) {
+    head = new LLI {
+        next=head;
+        // Any old code in the constructor
+        int tmp=arg;
+        while( arg > 10 ) {
+            tmp = tmp + arg;
+            arg = arg - 1;
+        }
+        i=tmp;
+    };
+    arg = arg-1;
+}
+if( !head ) return 0;
+LLI? next = head.next;
+if( !next ) return 1;
+return next.i;
+""");
+        StopNode stop = parser.parse().iterate();
+        assertEquals("Stop[ return 0; return 1; return .i; ]", stop.toString());
+        assertEquals(0L, Evaluator.evaluate(stop,  0));
+        assertEquals(1L, Evaluator.evaluate(stop,  1));
+        assertEquals(2L, Evaluator.evaluate(stop, 11));
+    }
+
+    @Test
+    public void testSquare() {
+        Parser parser = new Parser(
+"""
+struct Square {
+    flt side = arg;
+    // Newtons approximation to the square root, computed in a constructor.
+    // The actual allocation will copy in this result as the initial
+    // value for 'diag'.
+    flt diag = arg*arg/2;
+    while( 1 ) {
+        flt next = (side/diag + diag)/2;
+        if( next == diag ) break;
+        diag = next;
+    }
+};
+return new Square;
+""");
+        StopNode stop = parser.parse().iterate();
+        assertEquals("return Square;", stop.toString());
+        assertEquals("Obj<Square>{side=3.0,diag=1.7320508075688772}", Evaluator.evaluate(stop,  3).toString());
+        assertEquals("Obj<Square>{side=4.0,diag=2.0}", Evaluator.evaluate(stop, 4).toString());
+    }
+    static final String CONSTRUCTOR_MEMORY = """
+        struct S { int x; int y; };
+        struct T { int z=arg+40; };
+        T t = new T;
+        S a = new S { x=11; y=7; };
+        S b = new S { x=22; y=9; };
+        S p=a;
+        if (arg) p=b;
+        int before=p.x;
+        S c = new S {
+            x=p.x+1;
+            { int i=0; while (i<2) { p.y=p.y+1; i=i+1; } }
+            y=p.y;
+        };
+        p.x=33;
+        return before*10000+c.x*100+c.y+t.z;
+        """;
+
+    @Test public void testConstructorMemory() {
+        StopNode stop = new Parser(CONSTRUCTOR_MEMORY).parse().iterate();
+        assertEquals(111249L,Evaluator.evaluate(stop,0));
+        assertEquals(222352L,Evaluator.evaluate(stop,1));
+    }
+}
diff --git a/src/test/java/com/seaofnodes/simple/FuzzerWrap.java b/src/test/java/com/seaofnodes/simple/FuzzerWrap.java
index 52c2a014..2c98f405 100644
--- a/src/test/java/com/seaofnodes/simple/FuzzerWrap.java
+++ b/src/test/java/com/seaofnodes/simple/FuzzerWrap.java
@@ -1,10 +1,9 @@
 package com.seaofnodes.simple;
 
 import com.seaofnodes.simple.fuzzer.Fuzzer;
-import org.junit.Test;
+import java.util.Random;
 import org.junit.Ignore;
-
-
+import org.junit.Test;
 import static org.junit.Assert.assertTrue;
 
 /**
@@ -39,6 +38,15 @@ public class FuzzerWrap {
     }
 
 
+    @Test @Ignore
+    public void fuzzPeepsRandom() {
+        Random R = new Random(System.currentTimeMillis());
+        var fuzzer = new Fuzzer();
+        for (int i=0; i<100; i++)
+            fuzzer.fuzzPeeps(R.nextLong());
+        assertTrue(fuzzer.noExceptions());
+    }
+
     @Test
     @Ignore
     public void fuzzPeepTiming() {
diff --git a/src/test/java/com/seaofnodes/simple/SchedulerTest.java b/src/test/java/com/seaofnodes/simple/SchedulerTest.java
index ad595822..4b692f51 100644
--- a/src/test/java/com/seaofnodes/simple/SchedulerTest.java
+++ b/src/test/java/com/seaofnodes/simple/SchedulerTest.java
@@ -40,7 +40,7 @@ return i;
         Parser parser = new Parser("""
 struct S {
     int f;
-}
+};
 S v0=new S;
 if(arg) v0.f=1;
 return v0;
@@ -56,7 +56,7 @@ return v0;
         Parser parser = new Parser("""
 struct S {
     int f;
-}
+};
 S v=new S;
 v.f = 2;
 int i=new S.f;
diff --git a/src/test/java/com/seaofnodes/simple/TypeTest.java b/src/test/java/com/seaofnodes/simple/TypeTest.java
index cb45a0d7..6f7409cd 100644
--- a/src/test/java/com/seaofnodes/simple/TypeTest.java
+++ b/src/test/java/com/seaofnodes/simple/TypeTest.java
@@ -13,11 +13,11 @@ public class TypeTest {
     @Test
     public void testTypeAdHoc() {
         TypeStruct s1 = TypeStruct.make("s1", new Field[]{
-                Field.make("a",-1, TypeInteger.BOT),
-                Field.make("b",-2, TypeInteger.BOT) });
+                Field.make("a", TypeInteger.BOT,-1, false),
+                Field.make("b", TypeInteger.BOT,-2, false) });
         TypeStruct s2 = TypeStruct.make("s2", new Field[]{
-                Field.make("a",-3, TypeInteger.BOT),
-                Field.make("b",-4, TypeInteger.BOT) });
+                Field.make("a", TypeInteger.BOT,-3, false),
+                Field.make("b", TypeInteger.BOT,-4, false) });
         Assert.assertEquals(s1, s1.glb());
         Assert.assertNotEquals(s1, s1.dual());
         Assert.assertEquals(s1, s1.dual().glb());
diff --git a/src/test/java/com/seaofnodes/simple/evaluator/Evaluator.java b/src/test/java/com/seaofnodes/simple/evaluator/Evaluator.java
index 9eed23de..3eb406eb 100644
--- a/src/test/java/com/seaofnodes/simple/evaluator/Evaluator.java
+++ b/src/test/java/com/seaofnodes/simple/evaluator/Evaluator.java
@@ -100,7 +100,7 @@ public class Evaluator {
         }
         @Override
         public String toString() {
-            if (struct._name.equals("u8[]")) {
+            if (struct._name.equals("[u8]")) {
                 var sb = new StringBuilder();
                 for (int i=struct._fields.length-1; i<fields.length; i++) {
                     var v = fields[i];
@@ -192,28 +192,20 @@ public class Evaluator {
             if( n < 0 )
                 throw new NegativeArraySizeException(""+n);
             body = new Object[(int)n+1]; // Array body
-            var c = type._fields[type._fields.length-1]._type;
-            if (c instanceof TypeInteger) {
-                for (int i=0; i<n; i++) body[i+type._fields.length-1] = 0L;
-            } else if (c instanceof TypeFloat) {
-                for (int i = 0; i < n; i++) body[i+type._fields.length-1] = 0D;
+            var elem = type._fields[1]._type;
+            if (elem instanceof TypeInteger) {
+                for (int i=0; i<n; i++) body[i+1] = 0L;
+            } else if (elem instanceof TypeFloat) {
+                for (int i = 0; i < n; i++) body[i+1] = 0D;
             } else {
-                assert c instanceof TypeMemPtr;
+                assert elem instanceof TypeMemPtr;
             }
-            num = type._fields.length-1;
+            // Length value
+            body[0] = vall(alloc.in(3));
         } else {
-            body = new Object[type._fields.length];
-            num = type._fields.length;
-        }
-        for (int i=0; i<num; i++) {
-            var c = type._fields[i]._type;
-            if (c instanceof TypeInteger) {
-                body[i] = 0L;
-            } else if (c instanceof TypeFloat) {
-                body[i] = 0D;
-            } else {
-                assert c instanceof TypeMemPtr;
-            }
+            body = new Object[num = type._fields.length];
+            for (int i=0; i<num; i++)
+                body[i] = val(alloc.in(3+i));
         }
         return new Object[]{new Obj(type,body),MEMORY};
     }
diff --git a/src/test/java/com/seaofnodes/simple/evaluator/Scheduler.java b/src/test/java/com/seaofnodes/simple/evaluator/Scheduler.java
index 125f2f5e..afcc700f 100644
--- a/src/test/java/com/seaofnodes/simple/evaluator/Scheduler.java
+++ b/src/test/java/com/seaofnodes/simple/evaluator/Scheduler.java
@@ -557,7 +557,7 @@ public class Scheduler {
             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 RegionNode r -> new Block(arr, r, r._inputs.find(prev), new Block[1]);
                 case ReturnNode r -> new Block(arr, r, -1, new Block[0]);
                 default -> throw new AssertionError("Unexpected block exit node");
             });
diff --git a/src/test/java/com/seaofnodes/simple/fuzzer/ScriptGenerator.java b/src/test/java/com/seaofnodes/simple/fuzzer/ScriptGenerator.java
index 7cd854bf..d3cbb0ee 100644
--- a/src/test/java/com/seaofnodes/simple/fuzzer/ScriptGenerator.java
+++ b/src/test/java/com/seaofnodes/simple/fuzzer/ScriptGenerator.java
@@ -109,7 +109,7 @@ public class ScriptGenerator {
 
     static {
         new Parser("", TypeInteger.BOT);
-        for( var e : Parser.TYPES.entrySet() ) {
+        for( var e : Parser.defaultTypes().entrySet() ) {
             if( e.getValue() instanceof TypeInteger ) {
                 INTTYPES.add(new TypeInt(e.getKey()));
             }