adds array bounds checking

frog/member.dart

 // Copyright (c) 2012, 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 1120 matching lines @@
         return new Value(inferredResult, code, node.span);
       }
     } else if (target.type.isString) {
       if (name == ':index' && args.values[0].type.isNum) {
         return new Value(declaringType, '${target.code}[${argsCode[0]}]',
           node.span);
       } else if (name == ':add' && args.values[0].type.isNum) {
         return new Value(declaringType, '${target.code} + ${argsCode[0]}',
           node.span);
       }
-    } else if (declaringType.isNative) {
+    } else if (declaringType.isNative && options.disableBoundsChecks) {
       if (args.length > 0 && args.values[0].type.isNum) {
-        // TODO(jimhug): make more accurate/reliable
         if (name == ':index') {
-          return
-              new Value(returnType, '${target.code}[${argsCode[0]}]', node.span);
+          return new Value(returnType,
+            '${target.code}[${argsCode[0]}]', node.span);
         } else if (name == ':setindex') {
           return new Value(returnType,
               '${target.code}[${argsCode[0]}] = ${argsCode[1]}', node.span);
         }
       }
     }
 
     // TODO(jimhug): Optimize null on lhs as well.
     if (name == ':eq' || name == ':ne') {
       final op = name == ':eq' ? '==' : '!=';
@@ skipping 199 matching lines @@
   }
 
   void forEach(void f(Member member)) {
     factories.forEach((_, Map constructors) {
       constructors.forEach((_, Member member) {
         f(member);
       });
     });
   }
 }