Capture this.

frog/leg/elements/elements.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.
 
 #library('elements');
 
 #import('../tree/tree.dart');
 #import('../scanner/scannerlib.dart');
 #import('../leg.dart');  // TODO(karlklose): we only need type.
 #import('../util/util.dart');
@@ skipping 626 matching lines @@
             && !element.isInstanceMember()
             && (element.kind === ElementKind.FUNCTION);    
   }
 
   static bool isInstanceMethod(Element element) {
     return (element != null)
            && element.isInstanceMember()
            && (element.kind === ElementKind.FUNCTION);
   }
 
+  static bool isInstanceSend(Send send, TreeElements elements) {
+    Element element = elements[send];
+    if (element === null) return !isClosureSend(send, elements);
+    return isInstanceMethod(element) || isInstanceField(element);
+  }
+
   static bool isClosureSend(Send send, TreeElements elements) {
     if (send.isPropertyAccess) return false;
     if (send.receiver !== null) return false;
     Element element = elements[send];
     // (o)() or foo()().
     if (element === null && send.selector.asIdentifier() === null) return true;
     if (element === null) return false;
     // foo() with foo a local or a parameter.
     return element.isVariable() || element.isParameter();
   }
@@ skipping 24 matching lines @@
     else if (str === '>=') str = 'ge';
     else if (str === '>') str = 'gt';
     else if (str === '<=') str = 'le';
     else if (str === '<') str = 'lt';
     else if (str === '&' || str === '&=') str = 'and';
     else if (str === '^' || str === '^=') str = 'xor';
     else if (str === '|' || str === '|=') str = 'or';
     return new SourceString('$receiver\$$str');
   }
 }