Check constness of default args

frog/member.dart

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 /** A formal parameter to a [Method]. */
 class Parameter {
   FormalNode definition;
   Member method;
 
   String name;
@@ skipping 42 matching lines @@
     }
   }
 
   genValue(MethodMember method, MethodGenerator context) {
     if (definition.value == null || value != null) return;
 
     if (context == null) { // interface method
       context = new MethodGenerator(method, null);
     }
     value = definition.value.visit(context);
+    if (!value.isConst) {
+      world.error('default arguments must be constant', value.span);

[jimhug, 2011/12/06 16:23:39]

Pet peeve: 'default parameter values must be constant'

+    }
     value = value.convertTo(context, type, definition.value);
   }
 
   Parameter copyWithNewType(Member newMethod, Type newType) {
     var ret = new Parameter(definition, newMethod);
     ret.type = newType;
     ret.name = name;
     ret.isInitializer = isInitializer;
     return ret;
   }
@@ skipping 1649 matching lines @@
   }
 
   void forEach(void f(Member member)) {
     factories.forEach((_, Map constructors) {
       constructors.forEach((_, Member member) {
         f(member);
       });
     });
   }
 }