Resolve typedefs.

lib/compiler/implementation/elements/elements.dart

Index: lib/compiler/implementation/elements/elements.dart
diff --git a/lib/compiler/implementation/elements/elements.dart b/lib/compiler/implementation/elements/elements.dart
index 01dc5707385cb7b796a6e953e8bced1569a4e765..b5944249c990aeaf766f8a38208e33bf438a8f15 100644
--- a/lib/compiler/implementation/elements/elements.dart
+++ b/lib/compiler/implementation/elements/elements.dart
@@ -38,7 +38,7 @@ class ElementCategory {
 
   static final int IMPLIES_TYPE = CLASS | ALIAS | TYPE_VARIABLE;
 
-  static final int IS_EXTENDABLE = CLASS | ALIAS;
+  static final int IS_EXTENDABLE = CLASS;
 }
 
 class ElementKind {
@@ -198,6 +198,14 @@ class Element implements Hashable {
     return null;
   }
 
+  Element getEnclosingClassOrTypedef() {
+    for (Element e = this; e !== null; e = e.enclosingElement) {
+      if (e.kind === ElementKind.CLASS
+          || e.kind === ElementKind.TYPEDEF) return e;

[ahe, 2012/07/30 10:30:05]

I'd prefer if you keep the condition on the same line and the return on a line
by itself (preferably wrapped in curly braces).

[Johnni Winther, 2012/08/01 10:12:28]

Removed.

+    }
+    return null;
+  }
+
   Element getEnclosingMember() {
     for (Element e = this; e !== null; e = e.enclosingElement) {
       if (e.isMember()) return e;
@@ -419,16 +427,18 @@ class PrefixElement extends Element {
 }
 
 class TypedefElement extends Element {
+  TypedefElement(SourceString name, Element enclosing)
+    : typeParameters = new LinkedHashMap<SourceString, TypeVariableElement>(),
+      super(name, ElementKind.TYPEDEF, enclosing);
+
+  LinkedHashMap<SourceString, TypeVariableElement> typeParameters;

[ahe, 2012/07/30 10:30:05]

I don't think this should be a map. The overhead of using a map is huge and in
99% of the cases it will contain less than two elements.

[Johnni Winther, 2012/08/01 10:12:28]

Done.

+
   Type cachedType;
   Typedef cachedNode;
 
-  TypedefElement(SourceString name, Element enclosing)
-      : super(name, ElementKind.TYPEDEF, enclosing);
-
   Type computeType(Compiler compiler) {
     if (cachedType !== null) return cachedType;
-    cachedType = compiler.computeFunctionType(
-        this, compiler.resolveTypedef(this));
+    compiler.resolveTypedef(this);

[ahe, 2012/07/30 10:30:05]

This method may be called twice. You need to ensure that cachedType only is
assigned once and not by side-effect. I'm having a hard time seeing that
cachedType is only assigned once.

[Johnni Winther, 2012/08/01 10:12:28]

Done.

     return cachedType;
   }
 }