num implements Comparable and Hashable.

lib/compiler/implementation/js_backend/backend.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.
 
 typedef void Recompile(Element element);
 
 class ReturnInfo {
   HType returnType;
   List<Element> compiledFunctions;
 
@@ skipping 684 matching lines @@
     } else if (element == compiler.doubleClass) {
       return const SourceString('doubleTypeCheck');
     } else if (element == compiler.numClass) {
       return const SourceString('numTypeCheck');
     } else if (element == compiler.boolClass) {
       return const SourceString('boolTypeCheck');
     } else if (element == compiler.functionClass || element.isTypedef()) {
       return const SourceString('functionTypeCheck');
     } else if (element == compiler.intClass) {
       return const SourceString('intTypeCheck');
-    } else if (Elements.isStringSupertype(element, compiler)) {
+    } else if (Elements.isNumberOrStringSupertype(element, compiler)) {
+      if (nativeCheck) {

[kasperl, 2012/09/07 13:03:46]

Maybe use return ? : in these cases in this file?

[ngeoffray, 2012/09/07 14:06:36]

Done.

+        return const SourceString('numberOrStringSuperNativeTypeCheck');
+      } else {
+        return const SourceString('numberOrStringSuperTypeCheck');
+      }
+    } else if (Elements.isStringOnlySupertype(element, compiler)) {
       if (nativeCheck) {
         return const SourceString('stringSuperNativeTypeCheck');
       } else {
         return const SourceString('stringSuperTypeCheck');
       }
     } else if (element === compiler.listClass) {
       return const SourceString('listTypeCheck');
     } else {
       if (Elements.isListSupertype(element, compiler)) {
         if (nativeCheck) {
           return const SourceString('listSuperNativeTypeCheck');
         } else {
           return const SourceString('listSuperTypeCheck');
         }
       } else if (nativeCheck) {
         return const SourceString('callTypeCheck');
       } else {
         return const SourceString('propertyTypeCheck');
       }
     }
   }
 }