Make traceur.runtime.StopIteration into a constructor function.

src/runtime/runtime.js

Index: src/runtime/runtime.js 
diff --git a/src/runtime/runtime.js b/src/runtime/runtime.js 
index 8adf74a0944f5ce2c5c5ffa1360afee357e75a85..f953e3ddf6e5149234081dad02fabf0a6881972d 100644 
--- a/src/runtime/runtime.js 
+++ b/src/runtime/runtime.js 
@@ -338,43 +338,34 @@ traceur.runtime = (function(global) { 
 if (index < array.length) { 
 return array[index++]; 
 } 
- throw StopIterationLocal; 
+ throw new StopIterationLocal(); 
 } 
 }; 
 })); 
 } 
 
- // Generators 
- var StopIterationLocal; 
- var isStopIteration = function(x) { 
- return x === StopIterationLocal; 
+ // StopIteration 
+ var StopIterationLocal = function(v) { 
+ this.value = v; 
 }; 
 
- switch (typeof StopIteration) { 
- case 'function': 
- StopIterationLocal = new StopIteration(); 
- isStopIteration = function(x) { 
- return x instanceof StopIteration; 
- }; 
- break; 
- case 'object': 
- StopIterationLocal = StopIteration; 
- try { 
- // Firefox's StopIteration is both a valid lhs and rhs for instanceof. 
- StopIteration instanceof StopIteration; 
- 
- isStopIteration = function(x) { 
- return x instanceof StopIteration; 
- }; 
- } catch(e) {} 
- break; 
- case 'undefined': 
- StopIterationLocal = { 
- toString: function() { 
- return '[object StopIteration]'; 
- } 
- }; 
- global.StopIteration = StopIterationLocal; 
+ StopIterationLocal.prototype = { 
+ toString: function() { 
+ return '[object StopIteration]'; 
+ } 
+ }; 
+ 
+ global.StopIteration = new StopIterationLocal(); 
+ 
+ function isStopIteration(x) { 
+ return x instanceof StopIterationLocal; 
+ } 
+ 
+ function setStopIteration(StopIteration) { 
+ if (typeof StopIteration !== 'function') 
+ throw new TypeError('constructor function required'); 
+ StopIterationLocal = StopIteration; 
+ global.StopIteration = new StopIteration(); 
 } 
 
 /** 
@@ -487,6 +478,7 @@ traceur.runtime = (function(global) { 
 Deferred: Deferred, 
 StopIteration: StopIterationLocal, 
 isStopIteration: isStopIteration, 
+ setStopIteration: setStopIteration, 
 addIterator: addIterator, 
 assertName: assertName, 
 createName: NameModule.Name,