tor-browser

Map.js (6712B)

---

/* 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, MAP_SET_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]");

// Array Grouping proposal
//
// Map.groupBy ( items, callbackfn )
//
// https://tc39.es/proposal-array-grouping/#sec-map.groupby
function MapGroupBy(items, callbackfn) {
 // Step 1. (Call to GroupBy is inlined.)

 // GroupBy, step 1.
 if (IsNullOrUndefined(items)) {
   ThrowTypeError(
     JSMSG_UNEXPECTED_TYPE,
     DecompileArg(0, items),
     items === null ? "null" : "undefined"
   );
 }

 // GroupBy, step 2.
 if (!IsCallable(callbackfn)) {
   ThrowTypeError(JSMSG_NOT_FUNCTION, DecompileArg(1, callbackfn));
 }

 // Step 2.
 var C = GetBuiltinConstructor("Map");
 var map = new C();

 // GroupBy, step 3. (Not applicable in our implementation.)

 // GroupBy, step 4.
 var k = 0;

 // GroupBy, steps 4 and 6.
 for (var value of allowContentIter(items)) {
   // GroupBy, step 6.a. (Not applicable)
   assert(k < 2 ** 53 - 1, "out-of-memory happens before k exceeds 2^53 - 1");

   // GroupBy, steps 6.b-d. (Implicit through for-of loop.)

   // GroupBy, step 6.e.
   var key = callContentFunction(callbackfn, undefined, value, k);

   // GroupBy, step 6.f. (Implicit through for-of loop.)

   // GroupBy, step 6.g. (Not applicable)

   // GroupBy, step 6.h. (Implicit through std_Map_get.)

   // GroupBy, step 6.i. (Inlined call to AddValueToKeyedGroup.)
   var elements = callFunction(std_Map_get, map, key);
   if (elements === undefined) {
     callFunction(std_Map_set, map, key, [value]);
   } else {
     DefineDataProperty(elements, elements.length, value);
   }

   // GroupBy, step 6.j.
   k += 1;
 }

 // Step 3. (Result map already populated in the previous loop.)

 // Step 4.
 return map;
}

/**
* Upsert proposal
*
* Map.prototype.getOrInsertComputed ( key, callbackfn )
*
* https://tc39.es/proposal-upsert/
*/
function MapGetOrInsertComputed(key, callbackfn) {
 // Step 1.  Let M be the this value.
 var M = this;

 // Step 2.  Perform ? RequireInternalSlot(M, [[MapData]]).
 if (!IsObject(M) || (M = GuardToMapObject(M)) === null) {
   return callFunction(
     CallMapMethodIfWrapped,
     this,
     key,
     callbackfn,
     "MapGetOrInsertComputed"
   );
 }

 // Step 3.  If IsCallable(callbackfn) is false, throw a TypeError exception.
 if (!IsCallable(callbackfn)) {
   ThrowTypeError(JSMSG_NOT_FUNCTION, DecompileArg(1, callbackfn));
 }

 // Step 4.  Set key to CanonicalizeKeyedCollectionKey(key).
 // key === 0 is true for both -0 and +0
 if (key === 0) {
   key = 0;
 }
 // Step 5.  For each Record { [[Key]], [[Value]] } p of M.[[MapData]], do
 // Step 5.a.  If p.[[Key]] is not empty and SameValue(p.[[Key]], key) is true, return p.[[Value]].
 if (callFunction(std_Map_has, M, key)) {
   return callFunction(std_Map_get, M, key);
 }

 // Step 6.  Let value be ? Call(callbackfn, undefined, « key »).
 var value = callContentFunction(callbackfn, undefined, key);

 // Step 7.  For each Record { [[Key]], [[Value]] } p of M.[[MapData]], do
 // Step 7.a.  If p.[[Key]] is not empty and SameValue(p.[[Key]], key) is true, then
 // Step 7.a.i.  Set p.[[Value]] to value.
 // Step 8.  Let p be the Record { [[Key]]: key, [[Value]]: value }.
 // Step 9.  Append p to M.[[MapData]].
 callFunction(std_Map_set, M, key, value);

 // Step 7.a.ii, 10. Return value.
 return value;
}