frog: better binding of methods.

frog/member.dart

Index: frog/member.dart
diff --git a/frog/member.dart b/frog/member.dart
index d6b1b7d9a64837683e7cf7d27efc0ca4e58f1fd1..2a513e69e0afffef1d4b693c99e165c6093f8db6 100644
--- a/frog/member.dart
+++ b/frog/member.dart
@@ -33,7 +33,8 @@ class Parameter {
       if (method.name == ':call') {
         // TODO(jimhug): Need simpler way to detect "true" function types vs.
         //   regular methods being used as function types for closures.
-        if (method.definition.body == null) {
+        // TODO(sigmund): Disallow non-null default values for native calls?
+        if (method.definition.body == null && !method.isNative) {

[Jennifer Messerly, 2011/12/15 01:13:14]

what case was this change needed for?

[Siggi Cherem (dart-lang), 2011/12/15 04:35:56]

As I add support to bind native methods, I tried to write:

var m = "hi".substring;

that statement would display the error below because substring takes an optional
second argument. Seemed that this check was overly strict in this case.

           world.error('default value not allowed on function type',
             definition.span);
         }
@@ -115,7 +116,7 @@ class Member extends Element {
   bool get isOperator() => name.startsWith(':');
   bool get isCallMethod() => name == ':call';
 
-  bool get prefersPropertySyntax() => true;
+  bool get requiresPropertySyntax() => false;
   bool get requiresFieldSyntax() => false;
 
   bool get isNative() => false;
@@ -296,9 +297,6 @@ class FieldMember extends Member {
     }
   }
 
-  bool get prefersPropertySyntax() => false;
-  bool get requiresFieldSyntax() => isNative;
-
   void provideFieldSyntax() {} // Nothing to do.
   void providePropertySyntax() { _providePropertySyntax = true; }
 
@@ -462,11 +460,19 @@ class PropertyMember extends Member {
   bool get canGet() => getter != null;
   bool get canSet() => setter != null;
 
-  bool get prefersPropertySyntax() => true;
-  bool get requiresFieldSyntax() => false;
+  // If the property is just a declaration in an interface, continue to allow
+  // field syntax in the generated code.
+  bool get requiresPropertySyntax() => declaringType.isClass;
 
   void provideFieldSyntax() { _provideFieldSyntax = true; }
-  void providePropertySyntax() {}// Nothing to do.
+  void providePropertySyntax() {
+    // when overriding native fields, we still provide a field syntax to ensure
+    // that native functions will find the appropriate property implementation.
+    // TODO(sigmund): should check for this transitively...

[Jennifer Messerly, 2011/12/15 01:13:14]

could you just walk the chain of _overriddenFields?

[Siggi Cherem (dart-lang), 2011/12/15 04:35:56]

Currently we don't have a chain (PropertyMember._overridenField is a
FieldMember, which has nothing else above it). We would need to include
properties also (e.g. convert _overridenField into _overridenMember), and add it
also to FieldMembers.

+    if (_overriddenField != null && _overriddenField.isNative) {
+      provideFieldSyntax();
+    }
+  }
 
   // TODO(jimhug): Union of getter and setters sucks!
   bool get isStatic() => getter == null ? setter.isStatic : getter.isStatic;
@@ -608,7 +614,7 @@ class ConcreteMember extends Member {
   bool get isMethod() => baseMember.isMethod;
   bool get isProperty() => baseMember.isProperty;
 
-  bool get prefersPropertySyntax() => baseMember.prefersPropertySyntax;
+  bool get requiresPropertySyntax() => baseMember.requiresPropertySyntax;
   bool get requiresFieldSyntax() => baseMember.requiresFieldSyntax;
 
   void provideFieldSyntax() => baseMember.provideFieldSyntax();
@@ -710,9 +716,11 @@ class MethodMember extends Member {
 
   bool get isNative() => definition.nativeBody != null;
 
-  bool get canGet() => false; // TODO(jimhug): get bound method support.
+  bool get canGet() => true;
   bool get canSet() => false;
 
+  bool get requiresPropertySyntax() => true;
+
   SourceSpan get span() => definition == null ? null : definition.span;
 
   String get constructorName() {
@@ -789,9 +797,6 @@ class MethodMember extends Member {
     return -1;
   }
 
-  bool get prefersPropertySyntax() => true;
-  bool get requiresFieldSyntax() => false;
-
   void provideFieldSyntax() { _provideFieldSyntax = true; }
   void providePropertySyntax() { _providePropertySyntax = true; }
 
@@ -1485,16 +1490,9 @@ class MemberSet {
     if (_treatAsField == null) {
       // If this is the global MemberSet from world, always bind dynamically.
       // Note: we need this for proper noSuchMethod and REPL behavior.
-      _treatAsField = !isVar;
-      for (var member in members) {
-        if (member.requiresFieldSyntax) {
-          _treatAsField = true;
-          break;
-        }
-        if (member.prefersPropertySyntax) {
-          _treatAsField = false;
-        }
-      }
+      _treatAsField = !isVar && (members.some((m) => m.requiresFieldSyntax)
+          || members.every((m) => !m.requiresPropertySyntax));
+
       for (var member in members) {
         if (_treatAsField) {
           member.provideFieldSyntax();