Map/Set: Implement constructor parameter handling

src/collection.js

Index: src/collection.js
diff --git a/src/collection.js b/src/collection.js
index 0d8dd77f7bd3be944ffcd25b51544d8ebe740c00..f4bd549238cb96e89c27093dedd80f6ee0f732c3 100644
--- a/src/collection.js
+++ b/src/collection.js
@@ -12,15 +12,60 @@ var $Set = global.Set;
 var $Map = global.Map;
 
 
+// 7.4.1 CheckIterable ( obj )

[arv (Not doing code reviews), 2014/06/18 21:02:05]

This should probably go in v8natives.js once this file is no longer
experimental.

[rossberg, 2014/06/23 14:16:00]

Agreed. Maybe add a TODO to that end?

We could also consider calling it ToIterable or something -- the spec name is
really poorly chosen, and inconsistent with all other conversions. (I already
filed that with one of my chapter bugs.)

[arv (Not doing code reviews), 2014/06/23 15:43:56]

Done.

+function CheckIterable(obj) {
+  if (!IS_SPEC_OBJECT(obj)) {
+    return UNDEFINED;
+  }
+  return obj[symbolIterator];
+}
+
+
+// 7.4.2 GetIterator ( obj, method )
+function GetIterator(obj, method) {
+  if (IS_UNDEFINED(method)) {
+    method = CheckIterable(obj);
+  }
+  if (!IS_SPEC_FUNCTION(method)) {
+    throw MakeTypeError('not_iterable', [obj]);
+  }
+  var iterator = %_CallFunction(obj, method);
+  if (!IS_SPEC_OBJECT(iterator)) {
+    throw MakeTypeError('not_an_iterator', [iterator]);
+  }
+  return iterator;
+}
+
+
 // -------------------------------------------------------------------
 // Harmony Set
 
-function SetConstructor() {
-  if (%_IsConstructCall()) {
-    %SetInitialize(this);
-  } else {
+function SetConstructor(iterable) {
+  if (!%_IsConstructCall()) {
     throw MakeTypeError('constructor_not_function', ['Set']);
   }
+
+  var iter, adder;
+
+  if (!IS_NULL_OR_UNDEFINED(iterable)) {
+    iter = GetIterator(iterable);
+    adder = this.add;
+    if (!IS_SPEC_FUNCTION(adder)) {
+      throw MakeTypeError('property_not_function', ['add', this]);
+    }
+  }
+
+  %SetInitialize(this);
+
+  if (IS_UNDEFINED(iter)) return;
+
+  var next, done;
+  while (!(next = iter.next()).done) {
+    if (!IS_SPEC_OBJECT(next)) {
+      throw MakeTypeError('not_an_object', [next]);
+    }
+    %_CallFunction(this, next.value, adder);
+  }
 }
 
 
@@ -117,12 +162,36 @@ SetUpSet();
 // -------------------------------------------------------------------
 // Harmony Map
 
-function MapConstructor() {
-  if (%_IsConstructCall()) {
-    %MapInitialize(this);
-  } else {
+function MapConstructor(iterable) {
+  if (!%_IsConstructCall()) {
     throw MakeTypeError('constructor_not_function', ['Map']);
   }
+
+  var iter, adder;
+
+  if (!IS_NULL_OR_UNDEFINED(iterable)) {
+    iter = GetIterator(iterable);
+    adder = this.set;
+    if (!IS_SPEC_FUNCTION(adder)) {
+      throw MakeTypeError('property_not_function', ['set', this]);
+    }
+  }
+
+  %MapInitialize(this);
+
+  if (IS_UNDEFINED(iter)) return;
+
+  var next, done, nextItem;
+  while (!(next = iter.next()).done) {
+    if (!IS_SPEC_OBJECT(next)) {
+      throw MakeTypeError('not_an_object', [next]);

[rossberg, 2014/06/23 14:15:59]

We typically give more specific error messages in cases like these, where the
type error is internal to some library function. Perhaps e.g. 'iterator result
... is not an object', or (below) 'iterator value ... is not an entry'.

[arv (Not doing code reviews), 2014/06/23 15:43:56]

Great idea.

Done.

+    }
+    nextItem = next.value;
+    if (!IS_SPEC_OBJECT(nextItem)) {
+      throw MakeTypeError('not_an_object', [nextItem]);
+    }
+    %_CallFunction(this, nextItem[0], nextItem[1], adder);
+  }
 }