1 files changed, 133 insertions, 0 deletions
diff --git a/js/src/builtin/Map.js b/js/src/builtin/Map.js
new file mode 100644
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+++ b/js/src/builtin/Map.js
@@ -0,0 +1,133 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+// ES2017 draft rev 0e10c9f29fca1385980c08a7d5e7bb3eb775e2e4
+// 23.1.1.1 Map, steps 6-8
+function MapConstructorInit(iterable) {
+  var map = this;
+
+  // Step 6.a.
+  var adder = map.set;
+
+  // Step 6.b.
+  if (!IsCallable(adder)) {
+    ThrowTypeError(JSMSG_NOT_FUNCTION, typeof adder);
+  }
+
+  // Steps 6.c-8.
+  for (var nextItem of allowContentIter(iterable)) {
+    // Step 8.d.
+    if (!IsObject(nextItem)) {
+      ThrowTypeError(JSMSG_INVALID_MAP_ITERABLE, "Map");
+    }
+
+    // Steps 8.e-j.
+    callContentFunction(adder, map, nextItem[0], nextItem[1]);
+  }
+}
+
+// ES2018 draft rev f83aa38282c2a60c6916ebc410bfdf105a0f6a54
+// 23.1.3.5 Map.prototype.forEach ( callbackfn [ , thisArg ] )
+function MapForEach(callbackfn, thisArg = undefined) {
+  // Step 1.
+  var M = this;
+
+  // Steps 2-3.
+  if (!IsObject(M) || (M = GuardToMapObject(M)) === null) {
+    return callFunction(
+      CallMapMethodIfWrapped,
+      this,
+      callbackfn,
+      thisArg,
+      "MapForEach"
+    );
+  }
+
+  // Step 4.
+  if (!IsCallable(callbackfn)) {
+    ThrowTypeError(JSMSG_NOT_FUNCTION, DecompileArg(0, callbackfn));
+  }
+
+  // Steps 5-8.
+  var entries = callFunction(std_Map_entries, M);
+
+  // Inlined: MapIteratorNext
+  var mapIterationResultPair = globalMapIterationResultPair;
+
+  while (true) {
+    var done = GetNextMapEntryForIterator(entries, mapIterationResultPair);
+    if (done) {
+      break;
+    }
+
+    var key = mapIterationResultPair[0];
+    var value = mapIterationResultPair[1];
+    mapIterationResultPair[0] = null;
+    mapIterationResultPair[1] = null;
+
+    callContentFunction(callbackfn, thisArg, value, key, M);
+  }
+}
+
+var globalMapIterationResultPair = CreateMapIterationResultPair();
+
+function MapIteratorNext() {
+  // Step 1.
+  var O = this;
+
+  // Steps 2-3.
+  if (!IsObject(O) || (O = GuardToMapIterator(O)) === null) {
+    return callFunction(
+      CallMapIteratorMethodIfWrapped,
+      this,
+      "MapIteratorNext"
+    );
+  }
+
+  // Steps 4-5 (implemented in GetNextMapEntryForIterator).
+  // Steps 8-9 (omitted).
+
+  var mapIterationResultPair = globalMapIterationResultPair;
+
+  var retVal = { value: undefined, done: true };
+
+  // Step 10.a, 11.
+  var done = GetNextMapEntryForIterator(O, mapIterationResultPair);
+  if (!done) {
+    // Steps 10.b-c (omitted).
+
+    // Step 6.
+    var itemKind = UnsafeGetInt32FromReservedSlot(O, ITERATOR_SLOT_ITEM_KIND);
+
+    var result;
+    if (itemKind === ITEM_KIND_KEY) {
+      // Step 10.d.i.
+      result = mapIterationResultPair[0];
+    } else if (itemKind === ITEM_KIND_VALUE) {
+      // Step 10.d.ii.
+      result = mapIterationResultPair[1];
+    } else {
+      // Step 10.d.iii.
+      assert(itemKind === ITEM_KIND_KEY_AND_VALUE, itemKind);
+      result = [mapIterationResultPair[0], mapIterationResultPair[1]];
+    }
+
+    mapIterationResultPair[0] = null;
+    mapIterationResultPair[1] = null;
+    retVal.value = result;
+    retVal.done = false;
+  }
+
+  // Steps 7, 12.
+  return retVal;
+}
+
+// ES6 final draft 23.1.2.2.
+// Uncloned functions with `$` prefix are allocated as extended function
+// to store the original name in `SetCanonicalName`.
+function $MapSpecies() {
+  // Step 1.
+  return this;
+}
+SetCanonicalName($MapSpecies, "get [Symbol.species]");