Fixes to get Swarm demo working again.

frog/gen.dart

Index: frog/gen.dart
diff --git a/frog/gen.dart b/frog/gen.dart
index 74291fa7157be50fb590c26cd30d121d06009b0b..44c5a275bfcd50da307723e65c8db01ea0ce1839 100644
--- a/frog/gen.dart
+++ b/frog/gen.dart
@@ -17,6 +17,7 @@
 class WorldGenerator {
   MethodMember main;
   CodeWriter writer;
+  CodeWriter _mixins;
   Map<String, GlobalValue> globals;
   CoreJs corejs;
   bool _inheritsGenerated = false;
@@ -52,6 +53,9 @@ class WorldGenerator {
     // the topographic sort order.
     writeTypes(main.declaringType.library);
 
+    // Write out any inherited concrete members.
+    if (_mixins != null) writer.write(_mixins.text);
+
     _writeGlobals();
     writer.writeln('${mainCall.code};');
   }
@@ -192,9 +196,19 @@ class WorldGenerator {
 
     if (!type.isTop) {
       if (type is ConcreteType) {
+        ConcreteType c = type;
         _ensureInheritsHelper();
-        writer.writeln(
-            '\$inherits(${type.jsname}, ${type.genericType.jsname});');
+        writer.writeln('\$inherits(${c.jsname}, ${c.genericType.jsname});');
+
+        // Mixin members from concrete specializations of base types too.
+        // TODO(jmesserly): emit this sooner instead of at the end.
+        // But it needs to come after we've emitted both types.
+        // TODO(jmesserly): HACK: using _parent instead of parent so we don't
+        // try to inherit things that we didn't actually use.
+        for (var p = c._parent; p is ConcreteType; p = p._parent) {
+          _ensureInheritMembersHelper();
+          _mixins.writeln('\$inheritsMembers(${c.jsname}, ${p.jsname});');
+        }
       } else if (!type.isNativeType) {
         if (type.parent != null && !type.parent.isObject) {
           _ensureInheritsHelper();
@@ -278,6 +292,25 @@ function $inherits(child, parent) {
 }""");
   }
 
+  /**
+   * Generates the $inheritsMembers function when it's first used.
+   * This is used to mix in specialized generic members from the base class.
+   */
+  _ensureInheritMembersHelper() {
+    if (_mixins != null) return;
+    _mixins = new CodeWriter();
+    _mixins.comment('// ********** Generic Type Inheritance **************');
+    _mixins.writeln(@"""
+/** Implements extends for generic types. */
+function $inheritsMembers(child, parent) {
+  child = child.prototype;
+  parent = parent.prototype;
+  Object.getOwnPropertyNames(parent).forEach(function(name) {

[Jennifer Messerly, 2011/11/18 18:51:29]

Not sure if it makes sense to do this on the JS side. This is inspired by
traitjs, but simpler because we don't need to worry about conflict resolution,
enumerable/non-enumerable, etc.

I tried doing it in both the JS side and directly emitting the right assignments
in gen.dart--this version was smaller code, because I didn't need to duplicate
the logic from _writeType, _writeMethod, _writeField, _writeProperty, etc.

+    if (typeof(child[name]) == 'undefined') child[name] = parent[name];
+  });
+}""");
+  }
+
   _writeDynamicStubs(Type type) {
     if (type.varStubs != null) {
       for (var stub in orderValuesByKeys(type.varStubs)) {
@@ -787,11 +820,13 @@ class MethodGenerator implements TreeVisitor {
   writeBody() {
     var initializers = null;
     var initializedFields = null; // to check that final fields are initialized
+    var allMembers = null;
     if (method.isConstructor) {
       initializers = [];
       initializedFields = new Set();
-      for (var f in world.gen._orderValues(method.declaringType.getAllMembers())) {
-        if (f is FieldMember && !f.isStatic) {
+      allMembers = world.gen._orderValues(method.declaringType.getAllMembers());
+      for (var f in allMembers) {
+        if (f.isField && !f.isStatic) {

[Jennifer Messerly, 2011/11/18 18:51:29]

these can be ConcreteMembers too

           var cv = f.computeValue();
           if (cv != null) {
             initializers.add('this.${f.jsname} = ${cv.code}');
@@ -916,11 +951,10 @@ class MethodGenerator implements TreeVisitor {
 
     // check that initialization was correct
     if (initializedFields != null) {
-      for (var name in method.declaringType.members.getKeys()) {
-        var member = method.declaringType.members[name];
-        if (member is FieldMember && member.isFinal && !member.isStatic
-            && !initializedFields.contains(name)) {
-          world.error('Field "${name}" is final and was not initialized',
+      for (var member in allMembers) {

[Jennifer Messerly, 2011/11/18 18:51:29]

this fixes an inconsistency: the loop above was using getAllMembers, but this
one wasn't.

+        if (member.isField && member.isFinal && !member.isStatic
+            && !initializedFields.contains(member.name)) {
+          world.error('Field "${member.name}" is final and was not initialized',
               method.definition.span);
         }
       }