Record names of constructors and use that to implement Object.toString.

dart/frog/leg/lib/core.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.
 
 void print(var obj) {
   obj = obj.toString();
   var hasConsole = JS("bool", @"typeof console == 'object'");
   if (hasConsole) {
     JS("void", @"console.log($0)", obj);
   } else {
@@ skipping 30 matching lines @@
 
 bool isJSArray(var value) {
   return JS("bool", @"$0.constructor === Array", value);
 }
 
 
 add(var a, var b) {
   if (checkNumbers(a, b, "num+ expects a number as second operand.")) {
     return JS("num", @"$0 + $1", a, b);
   } else if (JS("bool", @"typeof $0 === 'string'", a)) {
     if (JS("bool", @"typeof $0 === 'string'", b) ||

[floitsch, 2012/01/11 11:52:40]

as discussed we should be able to just call b.toString.
But this can wait for another CL.

         JS("bool", @"typeof $0 === 'boolean'", b)) {
       return JS("String", @"$0 + $1", a, b);
     }
     if (JS("bool", @"typeof $0 === 'number'", b)) {
       if (JS("bool", @"$0 === 0 && (1/$0) < 0", b)) {
         return JS("String", @"$0 + '-0.0'", a);
       }
       return JS("String", @"$0 + $1", a, b);
     }
     if (b === null) return JS("String", @"$0 + 'null'", a);
-    if (isJSArray(b)) {
-      return JS("String", @"$0 + 'Instance of \'List\''", a);
-    }
     // No further native values.
-    b = UNINTERCEPTED(b.toString());
+    b = b.toString();
     if (JS("bool", @"typeof $0 === 'string'", b)) {
       return JS("String", @"$0 + $1", a, b);
     }
     // The following line is too long, but we can't break it using the +
     // operator, since that's what we are defining here.
     throw "calling toString() on right hand operand of operator + did not return a String";
   }
   throw "Unimplemented user-defined +.";
 }
 
@@ skipping 199 matching lines @@
   if (JS("bool", @"typeof $0 === 'string'", receiver) || isJSArray(receiver)) {
     return JS("num", @"$0.length", receiver);
   }
   throw "Unimplemented user-defined length.";
 }
 
 
 builtin$toString$0(var value) {
   if (JS("bool", @"typeof $0 == 'object'", value)) {
     if (isJSArray(value)) {
-      return "Instance of List";
+      return "Instance of 'List'";
     }
     return UNINTERCEPTED(value.toString());
   }
   if (JS("bool", @"$0 === 0 && (1 / $0) < 0", value)) {
     return "-0.0";
   }
   if (value === null) return "null";
   return JS("string", @"String($0)", value);
 }
 
 
 bool isInt(var v) {
   return JS("bool", @"($0 | 0) === $1", v, v);
 }
 
 class int {}
 class double {}
 class String {}
 class bool {}
-class Object {}
+class Object {
+  String toString() {
+    String name = JS('String', @'this.constructor.name');
+    if (name === null) {
+      name = JS('String', @'$0.match(/^\s*function\s*(\S*)\s*\(/)[1]',
+                JS('String', @'this.constructor.toString()'));
+    }
+    return "Instance of '$name'";
+  }
+}
 class List<T> {
   static void _checkConstructorInput(n) {
     // TODO(ngeoffray): Inline once we support optional parameters or
     // bailout.
     if (!isInt(n)) throw "Invalid argument";
     if (n < 0) throw "Negative size";
   }
 
   factory List(n) {
     // TODO(ngeoffray): Adjust to optional parameters.
@@ skipping 63 matching lines @@
     } else {
       return
         JS("num", @"Math.floor($0 + (Date.now() - $1))", elapsedMs, startMs);
     }
   }
 
   int frequency() {
     return 1000;
   }
 }