fixes #207: add a counter parameter to Array analogues that have them

Author: michaelficarra

spec.html

@@ -441,14 +441,16 @@ <h1>Iterator.prototype.map ( _mapper_ )</h1>
           1. Let _iterated_ be ? GetIteratorDirect(*this* value).
           1. If IsCallable(_mapper_) is *false*, throw a *TypeError* exception.
           1. Let _closure_ be a new Abstract Closure with no parameters that captures _iterated_ and _mapper_ and performs the following steps when called:
+            1. Let _counter_ be 0.
             1. Repeat,
               1. Let _next_ be ? IteratorStep(_iterated_).
               1. If _next_ is *false*, return *undefined*.
               1. Let _value_ be ? IteratorValue(_next_).
-              1. Let _mapped_ be Completion(Call(_mapper_, *undefined*, &laquo; _value_ &raquo;)).
+              1. Let _mapped_ be Completion(Call(_mapper_, *undefined*, &laquo; _value_, 𝔽(_counter_) &raquo;)).
               1. IfAbruptCloseIterator(_mapped_, _iterated_).
               1. Let _completion_ be Completion(Yield(_mapped_)).
               1. IfAbruptCloseIterator(_completion_, _iterated_).
+              1. Set _counter_ to _counter_ + 1.
           1. Return CreateIteratorFromClosure(_closure_, ~Iterator Helper~, %IteratorHelperPrototype%).
         </emu-alg>
       </emu-clause>
@@ -459,15 +461,17 @@ <h1>Iterator.prototype.filter ( _filterer_ )</h1>
           1. Let _iterated_ be ? GetIteratorDirect(*this* value).
           1. If IsCallable(_filterer_) is *false*, throw a *TypeError* exception.
           1. Let _closure_ be a new Abstract Closure with no parameters that captures _iterated_ and _filterer_ and performs the following steps when called:
+            1. Let _counter_ be 0.
             1. Repeat,
               1. Let _next_ be ? IteratorStep(_iterated_).
               1. If _next_ is *false*, return *undefined*.
               1. Let _value_ be ? IteratorValue(_next_).
-              1. Let _selected_ be Completion(Call(_filterer_, *undefined*, &laquo; _value_ &raquo;)).
+              1. Let _selected_ be Completion(Call(_filterer_, *undefined*, &laquo; _value_, 𝔽(_counter_) &raquo;)).
               1. IfAbruptCloseIterator(_selected_, _iterated_).
               1. If ToBoolean(_selected_) is *true*, then
                 1. Let _completion_ be Completion(Yield(_value_)).
                 1. IfAbruptCloseIterator(_completion_, _iterated_).
+              1. Set _counter_ to _counter_ + 1.
           1. Return CreateIteratorFromClosure(_closure_, ~Iterator Helper~, %IteratorHelperPrototype%).
         </emu-alg>
       </emu-clause>
@@ -530,9 +534,9 @@ <h1>Iterator.prototype.indexed ( )</h1>
               1. If _next_ is *false*, return *undefined*.
               1. Let _value_ be ? IteratorValue(_next_).
               1. Let _pair_ be CreateArrayFromList(&laquo; 𝔽(_index_), _value_ &raquo;).
-              1. Set _index_ to _index_ + 1.
               1. Let _completion_ be Completion(Yield(_pair_)).
               1. IfAbruptCloseIterator(_completion_, _iterated_).
+              1. Set _index_ to _index_ + 1.
           1. Return CreateIteratorFromClosure(_closure_, ~Iterator Helper~, %IteratorHelperPrototype%).
         </emu-alg>
       </emu-clause>
@@ -543,11 +547,12 @@ <h1>Iterator.prototype.flatMap ( _mapper_ )</h1>
           1. Let _iterated_ be ? GetIteratorDirect(*this* value).
           1. If IsCallable(_mapper_) is *false*, throw a *TypeError* exception.
           1. Let _closure_ be a new Abstract Closure with no parameters that captures _iterated_ and _mapper_ and performs the following steps when called:
+            1. Let _counter_ be 0.
             1. Repeat,
               1. Let _next_ be ? IteratorStep(_iterated_).
               1. If _next_ is *false*, return *undefined*.
               1. Let _value_ be ? IteratorValue(_next_).
-              1. Let _mapped_ be Completion(Call(_mapper_, *undefined*, &laquo; _value_ &raquo;)).
+              1. Let _mapped_ be Completion(Call(_mapper_, *undefined*, &laquo; _value_, 𝔽(_counter_) &raquo;)).
               1. IfAbruptCloseIterator(_mapped_, _iterated_).
               1. Let _innerIterator_ be Completion(GetIterator(_mapped_, ~sync~)).
               1. IfAbruptCloseIterator(_innerIterator_, _iterated_).
@@ -565,6 +570,7 @@ <h1>Iterator.prototype.flatMap ( _mapper_ )</h1>
                     1. Let _backupCompletion_ be Completion(IteratorClose(_innerIterator_, _completion_)).
                     1. IfAbruptCloseIterator(_backupCompletion_, _iterated_).
                     1. Return ? IteratorClose(_completion_, _iterated_).
+              1. Set _counter_ to _counter_ + 1.
           1. Return CreateIteratorFromClosure(_closure_, ~Iterator Helper~, %IteratorHelperPrototype%).
         </emu-alg>
       </emu-clause>
@@ -580,13 +586,15 @@ <h1>Iterator.prototype.reduce ( _reducer_ [ , _initialValue_ ] )</h1>
             1. Let _accumulator_ be ? IteratorValue(_next_).
           1. Else,
             1. Let _accumulator_ be _initialValue_.
+          1. Let _counter_ be 0.
           1. Repeat,
             1. Let _next_ be ? IteratorStep(_iterated_).
             1. If _next_ is *false*, return _accumulator_.
             1. Let _value_ be ? IteratorValue(_next_).
-            1. Let _result_ be Completion(Call(_reducer_, *undefined*, &laquo; _accumulator_, _value_ &raquo;)).
+            1. Let _result_ be Completion(Call(_reducer_, *undefined*, &laquo; _accumulator_, _value_, 𝔽(_counter_) &raquo;)).
             1. IfAbruptCloseIterator(_result_, _iterated_).
             1. Set _accumulator_ to _result_.[[Value]].
+            1. Set _counter_ to _counter_ + 1.
         </emu-alg>
       </emu-clause>
 
@@ -619,12 +627,14 @@ <h1>Iterator.prototype.forEach ( _fn_ )</h1>
         <emu-alg>
           1. Let _iterated_ be ? GetIteratorDirect(*this* value).
           1. If IsCallable(_fn_) is *false*, throw a *TypeError* exception.
+          1. Let _counter_ be 0.
           1. Repeat,
             1. Let _next_ be ? IteratorStep(_iterated_).
             1. If _next_ is *false*, return *undefined*.
             1. Let _value_ be ? IteratorValue(_next_).
-            1. Let _result_ be Completion(Call(_fn_, *undefined*, &laquo; _value_ &raquo;)).
+            1. Let _result_ be Completion(Call(_fn_, *undefined*, &laquo; _value_, 𝔽(_counter_) &raquo;)).
             1. IfAbruptCloseIterator(_result_, _iterated_).
+            1. Set _counter_ to _counter_ + 1.
         </emu-alg>
       </emu-clause>
 
@@ -633,13 +643,15 @@ <h1>Iterator.prototype.some ( _fn_ )</h1>
         <emu-alg>
           1. Let _iterated_ be ? GetIteratorDirect(*this* value).
           1. If IsCallable(_fn_) is *false*, throw a *TypeError* exception.
+          1. Let _counter_ be 0.
           1. Repeat,
             1. Let _next_ be ? IteratorStep(_iterated_).
             1. If _next_ is *false*, return *false*.
             1. Let _value_ be ? IteratorValue(_next_).
-            1. Let _result_ be Completion(Call(_fn_, *undefined*, &laquo; _value_ &raquo;)).
+            1. Let _result_ be Completion(Call(_fn_, *undefined*, &laquo; _value_, 𝔽(_counter_) &raquo;)).
             1. IfAbruptCloseIterator(_result_, _iterated_).
             1. If ToBoolean(_result_) is *true*, return ? IteratorClose(_iterated_, NormalCompletion(*true*)).
+            1. Set _counter_ to _counter_ + 1.
         </emu-alg>
       </emu-clause>
 
@@ -648,13 +660,15 @@ <h1>Iterator.prototype.every ( _fn_ )</h1>
         <emu-alg>
           1. Let _iterated_ be ? GetIteratorDirect(*this* value).
           1. If IsCallable(_fn_) is *false*, throw a *TypeError* exception.
+          1. Let _counter_ be 0.
           1. Repeat,
             1. Let _next_ be ? IteratorStep(_iterated_).
             1. If _next_ is *false*, return *true*.
             1. Let _value_ be ? IteratorValue(_next_).
-            1. Let _result_ be Completion(Call(_fn_, *undefined*, &laquo; _value_ &raquo;)).
+            1. Let _result_ be Completion(Call(_fn_, *undefined*, &laquo; _value_, 𝔽(_counter_) &raquo;)).
             1. IfAbruptCloseIterator(_result_, _iterated_).
             1. If ToBoolean(_result_) is *false*, return ? IteratorClose(_iterated_, NormalCompletion(*false*)).
+            1. Set _counter_ to _counter_ + 1.
         </emu-alg>
       </emu-clause>
 
@@ -663,13 +677,15 @@ <h1>Iterator.prototype.find ( _fn_ )</h1>
         <emu-alg>
           1. Let _iterated_ be ? GetIteratorDirect(*this* value).
           1. If IsCallable(_fn_) is *false*, throw a *TypeError* exception.
+          1. Let _counter_ be 0.
           1. Repeat,
             1. Let _next_ be ? IteratorStep(_iterated_).
             1. If _next_ is *false*, return *undefined*.
             1. Let _value_ be ? IteratorValue(_next_).
-            1. Let _result_ be Completion(Call(_fn_, *undefined*, &laquo; _value_ &raquo;)).
+            1. Let _result_ be Completion(Call(_fn_, *undefined*, &laquo; _value_, 𝔽(_counter_) &raquo;)).
             1. IfAbruptCloseIterator(_result_, _iterated_).
             1. If ToBoolean(_result_) is *true*, return ? IteratorClose(_iterated_, NormalCompletion(_value_)).
+            1. Set _counter_ to _counter_ + 1.
         </emu-alg>
       </emu-clause>
 
@@ -700,16 +716,18 @@ <h1>AsyncIterator.prototype.map ( _mapper_ )</h1>
           1. Let _iterated_ be ? GetIteratorDirect(*this* value).
           1. If IsCallable(_mapper_) is *false*, throw a *TypeError* exception.
           1. Let _closure_ be a new Abstract Closure with no parameters that captures _iterated_ and _mapper_ and performs the following steps when called:
+            1. Let _counter_ be 0.
             1. Repeat,
               1. Let _next_ be ? Await(? IteratorNext(_iterated_)).
               1. If ? IteratorComplete(_next_) is *true*, return *undefined*.
               1. Let _value_ be ? IteratorValue(_next_).
-              1. Let _mapped_ be Completion(Call(_mapper_, *undefined*, &laquo; _value_ &raquo;)).
+              1. Let _mapped_ be Completion(Call(_mapper_, *undefined*, &laquo; _value_, 𝔽(_counter_) &raquo;)).
               1. IfAbruptCloseAsyncIterator(_mapped_, _iterated_).
               1. Set _mapped_ to Completion(Await(_mapped_)).
               1. IfAbruptCloseAsyncIterator(_mapped_, _iterated_).
               1. Let _completion_ be Completion(Yield(_mapped_)).
               1. IfAbruptCloseAsyncIterator(_completion_, _iterated_).
+              1. Set _counter_ to _counter_ + 1.
           1. Return CreateAsyncIteratorFromClosure(_closure_, ~Async Iterator Helper~, %AsyncIteratorHelperPrototype%).
         </emu-alg>
       </emu-clause>
@@ -720,17 +738,19 @@ <h1>AsyncIterator.prototype.filter ( _filterer_ )</h1>
           1. Let _iterated_ be ? GetIteratorDirect(*this* value).
           1. If IsCallable(_filterer_) is *false*, throw a *TypeError* exception.
           1. Let _closure_ be a new Abstract Closure with no parameters that captures _iterated_ and _filterer_ and performs the following steps when called:
+            1. Let _counter_ be 0.
             1. Repeat,
               1. Let _next_ be ? Await(? IteratorNext(_iterated_)).
               1. If ? IteratorComplete(_next_) is *true*, return *undefined*.
               1. Let _value_ be ? IteratorValue(_next_).
-              1. Let _selected_ be Completion(Call(_filterer_, *undefined*, &laquo; _value_ &raquo;)).
+              1. Let _selected_ be Completion(Call(_filterer_, *undefined*, &laquo; _value_, 𝔽(_counter_) &raquo;)).
               1. IfAbruptCloseAsyncIterator(_selected_, _iterated_).
               1. Set _selected_ to Completion(Await(_selected_)).
               1. IfAbruptCloseAsyncIterator(_selected_, _iterated_).
               1. If ToBoolean(_selected_) is *true*, then
                 1. Let _completion_ be Completion(Yield(_value_)).
                 1. IfAbruptCloseAsyncIterator(_completion_, _iterated_).
+              1. Set _counter_ to _counter_ + 1.
           1. Return CreateAsyncIteratorFromClosure(_closure_, ~Async Iterator Helper~, %AsyncIteratorHelperPrototype%).
         </emu-alg>
       </emu-clause>
@@ -793,9 +813,9 @@ <h1>AsyncIterator.prototype.indexed ( )</h1>
               1. If ? IteratorComplete(_next_) is *true*, return *undefined*.
               1. Let _value_ be ? IteratorValue(_next_).
               1. Let _pair_ be CreateArrayFromList(&laquo; _index_, _value_ &raquo;).
-              1. Set _index_ to _index_ + 1.
               1. Let _completion_ be Completion(Yield(_pair_)).
               1. IfAbruptCloseAsyncIterator(_completion_, _iterated_).
+              1. Set _index_ to _index_ + 1.
           1. Return CreateAsyncIteratorFromClosure(_closure_, ~Async Iterator Helper~, %AsyncIteratorHelperPrototype%).
         </emu-alg>
       </emu-clause>
@@ -807,11 +827,12 @@ <h1>AsyncIterator.prototype.flatMap ( _mapper_ )</h1>
           1. Let _iterated_ be ? GetIteratorDirect(*this* value).
           1. If IsCallable(_mapper_) is *false*, throw a *TypeError* exception.
           1. Let _closure_ be a new Abstract Closure with no parameters that captures _iterated_ and _mapper_ and performs the following steps when called:
+            1. Let _counter_ be 0.
             1. Repeat,
               1. Let _next_ be ? Await(? IteratorNext(_iterated_)).
               1. If ? IteratorComplete(_next_) is *true*, return *undefined*.
               1. Let _value_ be ? IteratorValue(_next_).
-              1. Let _mapped_ be Completion(Call(_mapper_, *undefined*, &laquo; _value_ &raquo;)).
+              1. Let _mapped_ be Completion(Call(_mapper_, *undefined*, &laquo; _value_, 𝔽(_counter_) &raquo;)).
               1. IfAbruptCloseAsyncIterator(_mapped_, _iterated_).
               1. Set _mapped_ to Completion(Await(_mapped_)).
               1. IfAbruptCloseAsyncIterator(_mapped_, _iterated_).
@@ -838,6 +859,7 @@ <h1>AsyncIterator.prototype.flatMap ( _mapper_ )</h1>
                   1. Else if _completion_ is a throw completion, then
                     1. Assert: Awaiting _innerValue_ during the Yield on step <emu-xref href="#step-async-iterator-flatmap-yield"></emu-xref> threw.
                     1. Return ? IteratorClose(_completion_, _iterated_).
+              1. Set _counter_ to _counter_ + 1.
           1. Return CreateAsyncIteratorFromClosure(_closure_, ~Async Iterator Helper~, %AsyncIteratorHelperPrototype%).
         </emu-alg>
       </emu-clause>
@@ -853,15 +875,17 @@ <h1>AsyncIterator.prototype.reduce ( _reducer_ [ , _initialValue_ ] )</h1>
             1. Let _accumulator_ be ? IteratorValue(_next_).
           1. Else,
             1. Let _accumulator_ be _initialValue_.
+          1. Let _counter_ be 0.
           1. Repeat,
             1. Let _next_ be ? Await(? IteratorNext(_iterated_)).
             1. If ? IteratorComplete(_next_) is *true*, return _accumulator_.
             1. Let _value_ be ? IteratorValue(_next_).
-            1. Let _result_ be Completion(Call(_reducer_, *undefined*, &laquo; _accumulator_, _value_ &raquo;)).
+            1. Let _result_ be Completion(Call(_reducer_, *undefined*, &laquo; _accumulator_, _value_, 𝔽(_counter_) &raquo;)).
             1. IfAbruptCloseAsyncIterator(_result_, _iterated_).
             1. Set _result_ to Await(_result_).
             1. IfAbruptCloseAsyncIterator(_result_, _iterated_).
             1. Set _accumulator_ to _result_.
+            1. Set _counter_ to _counter_ + 1.
         </emu-alg>
       </emu-clause>
 
@@ -885,14 +909,16 @@ <h1>AsyncIterator.prototype.forEach ( _fn_ )</h1>
         <emu-alg>
           1. Let _iterated_ be ? GetIteratorDirect(*this* value).
           1. If IsCallable(_fn_) is *false*, throw a *TypeError* exception.
+          1. Let _counter_ be 0.
           1. Repeat,
             1. Let _next_ be ? Await(? IteratorNext(_iterated_)).
             1. If ? IteratorComplete(_next_) is *true*, return *undefined*.
             1. Let _value_ be ? IteratorValue(_next_).
-            1. Let _r_ be Completion(Call(_fn_, *undefined*, &laquo; _value_ &raquo;)).
+            1. Let _r_ be Completion(Call(_fn_, *undefined*, &laquo; _value_, 𝔽(_counter_) &raquo;)).
             1. IfAbruptCloseAsyncIterator(_r_, _iterated_).
             1. Set _r_ to Await(r).
             1. IfAbruptCloseAsyncIterator(_r_, _iterated_).
+            1. Set _counter_ to _counter_ + 1.
         </emu-alg>
       </emu-clause>
 
@@ -902,15 +928,17 @@ <h1>AsyncIterator.prototype.some ( _fn_ )</h1>
         <emu-alg>
           1. Let _iterated_ be ? GetIteratorDirect(*this* value).
           1. If IsCallable(_fn_) is *false*, throw a *TypeError* exception.
+          1. Let _counter_ be 0.
           1. Repeat,
             1. Let _next_ be ? Await(? IteratorNext(_iterated_)).
             1. If ? IteratorComplete(_next_) is *true*, return *false*.
             1. Let _value_ be ? IteratorValue(_next_).
-            1. Let _result_ be Completion(Call(_fn_, *undefined*, &laquo; _value_ &raquo;)).
+            1. Let _result_ be Completion(Call(_fn_, *undefined*, &laquo; _value_, 𝔽(_counter_) &raquo;)).
             1. IfAbruptCloseAsyncIterator(_result_, _iterated_).
             1. Set _result_ to Await(_result_).
             1. IfAbruptCloseAsyncIterator(_result_, _iterated_).
             1. If ToBoolean(_result_) is *true*, return ? AsyncIteratorClose(_iterated_, NormalCompletion(*true*)).
+            1. Set _counter_ to _counter_ + 1.
         </emu-alg>
       </emu-clause>
 
@@ -920,15 +948,17 @@ <h1>AsyncIterator.prototype.every ( _fn_ )</h1>
         <emu-alg>
           1. Let _iterated_ be ? GetIteratorDirect(*this* value).
           1. If IsCallable(_fn_) is *false*, throw a *TypeError* exception.
+          1. Let _counter_ be 0.
           1. Repeat,
             1. Let _next_ be ? Await(? IteratorNext(_iterated_)).
             1. If ? IteratorComplete(_next_) is *true*, return *true*.
             1. Let _value_ be ? IteratorValue(_next_).
-            1. Let _result_ be Completion(Call(_fn_, *undefined*, &laquo; _value_ &raquo;)).
+            1. Let _result_ be Completion(Call(_fn_, *undefined*, &laquo; _value_, 𝔽(_counter_) &raquo;)).
             1. IfAbruptCloseAsyncIterator(_result_, _iterated_).
             1. Set _result_ to Await(_result_).
             1. IfAbruptCloseAsyncIterator(_result_, _iterated_).
             1. If ToBoolean(_result_) is *false*, return ? AsyncIteratorClose(_iterated_, NormalCompletion(*false*)).
+            1. Set _counter_ to _counter_ + 1.
         </emu-alg>
       </emu-clause>
 
@@ -938,15 +968,17 @@ <h1>AsyncIterator.prototype.find ( _fn_ )</h1>
         <emu-alg>
           1. Let _iterated_ be ? GetIteratorDirect(*this* value).
           1. If IsCallable(_fn_) is *false*, throw a *TypeError* exception.
+          1. Let _counter_ be 0.
           1. Repeat,
             1. Let _next_ be ? Await(? IteratorNext(_iterated_)).
             1. If ? IteratorComplete(_next_) is *true*, return *undefined*.
             1. Let _value_ be ? IteratorValue(_next_).
-            1. Let _result_ be Completion(Call(_fn_, *undefined*, &laquo; _value_ &raquo;)).
+            1. Let _result_ be Completion(Call(_fn_, *undefined*, &laquo; _value_, 𝔽(_counter_) &raquo;)).
             1. IfAbruptCloseAsyncIterator(_result_, _iterated_).
             1. Set _result_ to Await(_result_).
             1. IfAbruptCloseAsyncIterator(_result_, _iterated_).
             1. If ToBoolean(_result_) is *true*, return ? AsyncIteratorClose(_iterated_, NormalCompletion(_value_)).
+            1. Set _counter_ to _counter_ + 1.
         </emu-alg>
       </emu-clause>