Straighten out nested forward ref type errors

2 files changed, 33 insertions, 17 deletions

diff --git a/chapter17/src/main/java/com/seaofnodes/simple/Parser.java b/chapter17/src/main/java/com/seaofnodes/simple/Parser.java
index c144b1d7..2e707096 100644
--- a/chapter17/src/main/java/com/seaofnodes/simple/Parser.java
+++ b/chapter17/src/main/java/com/seaofnodes/simple/Parser.java
@@ -666,24 +666,22 @@ public class Parser {
             return posT(old1);
         Type t1 = t0 == null ? TypeMemPtr.make(TypeStruct.makeFRef(tname)) : t0; // Null: assume a forward ref type
         // Nest arrays and '?' as needed
+        Type t2 = t1;
         while( true ) {
-            assert !(t1 instanceof TypeStruct);
+            assert !(t2 instanceof TypeStruct);
             if( match("?") ) {
-                if( !(t1 instanceof TypeMemPtr tmp) )
+                if( !(t2 instanceof TypeMemPtr tmp) )
                     throw error("Type "+t0+" cannot be null");
-                if( tmp._nil ) throw error("Type "+t1+" already allows null");
-                t1 = TypeMemPtr.make(tmp._obj,true);
-                continue;
-            }
-            if( match("[]") ) {
-                t1 = typeAry(t1);
-                continue;
-            }
-            break;
+                if( tmp._nil ) throw error("Type "+t2+" already allows null");
+                t2 = TypeMemPtr.make(tmp._obj,true);
+            } else if( match("[]") ) {
+                t2 = typeAry(t2);
+            } else
+                break;
         }
 
         // Check no forward ref
-        if( t0 != null ) return t1;
+        if( t0 != null ) return t2;
         // Check valid forward ref, after parsing all the type extra bits.
         // Cannot check earlier, because cannot find required 'id' until after "[]?" syntax
         int old2 = pos();
@@ -692,9 +690,8 @@ public class Parser {
         if( id==null )
             return posT(old1);  // Reset lexer to reparse
         // Yes a forward ref, so declare it
-        Type t2 = t1 instanceof TypeMemPtr tmp ? tmp.makeFrom(false): t1;
-        TYPES.put(tname,t2);
-        return t1;
+        TYPES.put(tname,t1);
+        return t2;
     }
 
     // Make an array type of t
diff --git a/chapter17/src/test/java/com/seaofnodes/simple/Chapter17Test.java b/chapter17/src/test/java/com/seaofnodes/simple/Chapter17Test.java
index 516da849..44538965 100644
--- a/chapter17/src/test/java/com/seaofnodes/simple/Chapter17Test.java
+++ b/chapter17/src/test/java/com/seaofnodes/simple/Chapter17Test.java
@@ -12,7 +12,12 @@ public class Chapter17Test {
     @Test
     public void testJig() {
         Parser parser = new Parser("""
-return 3.14;
+struct A { int i; };
+A! a = new A;
+a.i=a;
+a.i=2;
+return a;
+                                   //return 3.14;
 """);
         StopNode stop = parser.parse().iterate();
         assertEquals("return 3.14;", stop.toString());
@@ -369,7 +374,7 @@ for(;;arg++;) {}
 
     // ---------------------------------------------------------------
     @Test
-    public void testForward() {
+    public void testForward0() {
         Parser parser = new Parser("""
 struct A{
     B? f1;
@@ -382,6 +387,20 @@ return new A;
         assertEquals("Obj<A>{f1=null,f2=null}", Evaluator.evaluate(stop).toString());
     }
 
+    @Test
+    public void testForward1() {
+        Parser parser = new Parser("""
+struct A{
+    B?[]? nil_array_of_b;
+    B?[]  not_array_of_b = new B?[0];
+};
+return new A.not_array_of_b;
+""");
+        StopNode stop = parser.parse().iterate();
+        assertEquals("return (const)[*B?];", stop.toString());
+        assertEquals("Obj<[*B?]>{#=0,[]=[]}", Evaluator.evaluate(stop).toString());
+    }
+
     // ---------------------------------------------------------------
     @Test
     public void testLinkedList2() {