frog: better binding of methods.

frog/gen.dart

Index: frog/gen.dart
diff --git a/frog/gen.dart b/frog/gen.dart
index c518d2e13b5566f263f7a0b10fbbb1d6d47d998a..57ba1be3c79f269f9eda99e5cd45ee5eb9686a75 100644
--- a/frog/gen.dart
+++ b/frog/gen.dart
@@ -48,6 +48,10 @@ class WorldGenerator {
       world.coreimpl.types['StringImplementation'].markUsed();
       genMethod(
           world.coreimpl.types['StringImplementation'].getMember('contains'));
+      if (world.corelib.types['String'].isUsed) {
+        // 'String.split' creates a list.
+        world.coreimpl.types['ListFactory'].markUsed();
+      }
     }
 
     // Only include isolate-specific code if isolates are used.
@@ -225,6 +229,16 @@ class WorldGenerator {
     }
   }
 
+  String _boundMethod(Type type, String name) {
+    if (type.isSingletonNative) {
+      return '${type.jsname}.$name.bind(${type.jsname})';
+    } else if (type.isHiddenNativeType) {
+      return 'Object.getPrototype(this).${type.jsname}.bind(this)';
+    } else {
+      return '${type.jsname}.prototype.$name.bind(this)';
+    }
+  }
+
   _maybeIsTest(Type onType, Type checkType) {
     bool isSubtype = onType.isSubtypeOf(checkType);
     if (checkType.isTested) {
@@ -466,9 +480,12 @@ function $inheritsMembers(child, parent) {
     }
   }
 
-  _writeMethod(Member method) {
-    if (method.generator != null) {
-      method.generator.writeDefinition(writer, null);
+  _writeMethod(Member m) {
+    if (m.generator != null) {
+      m.generator.writeDefinition(writer, null);
+    } else if (m is MethodMember && m.isNative
+        && m.dynamic._providePropertySyntax && !m.dynamic._provideFieldSyntax) {
+      MethodGenerator._maybeGenerateBoundGetter(m, writer);
     }
   }
 
@@ -862,17 +879,23 @@ class MethodGenerator implements TreeVisitor {
 
     if (method is MethodMember) {
       MethodMember m = method;
-      if (m._providePropertySyntax) {
-        defWriter.enterBlock('${m.declaringType.jsname}.prototype'
-            + '.get\$${m.jsname} = function() {');
-        // TODO(jimhug): Bind not available in older Safari, need fallback?
-        defWriter.writeln('return ${m.declaringType.jsname}.prototype.'
-            + '${m.jsname}.bind(this);');
-        defWriter.exitBlock('}');
-
-        if (m._provideFieldSyntax) {
-          world.internalError('bound m accessed with field syntax');
-        }
+      _maybeGenerateBoundGetter(m, defWriter);
+    }
+  }
+
+  static _maybeGenerateBoundGetter(MethodMember m, CodeWriter defWriter) {
+    if (m._providePropertySyntax && !m.declaringType.isSingletonNative) {
+      defWriter.enterBlock(
+          world.gen._prototypeOf(m.declaringType, "get\$" + m.jsname) 
+          + ' = function() {');
+      // TODO(jimhug): Bind not available in older Safari, need fallback?
+      defWriter.writeln('return '
+          + world.gen._boundMethod(m.declaringType, m.jsname));
+      defWriter.exitBlock('}');
+
+      if (m._provideFieldSyntax) {
+        world.internalError('bound "${m.name}" accessed with field syntax',
+            m.definition.span);
       }
     }
   }
@@ -1459,8 +1482,9 @@ class MethodGenerator implements TreeVisitor {
     // Special path for list for readability and perf optimization.
     if (list.type.isList) {
       var tmpi = _scope.create('\$i', world.numType, null);
+      var listLength = listVar.get_(this, 'length', node.list);
       writer.enterBlock('for (var ${tmpi.code} = 0;' +
-          '${tmpi.code} < ${listVar.code}.length; ${tmpi.code}++) {');
+          '${tmpi.code} < ${listLength.code}; ${tmpi.code}++) {');
       var value = listVar.invoke(this, ':index', node.list,
           new Arguments(null, [tmpi]));
       writer.writeln('var ${item.code} = ${value.code};');