New Set methods

1Formal informations

2Set.prototype.union(iterable)

When the union method is called with argument iterable, the following steps are taken:

  1. Let set be the this value.
  2. If Type(set) is not Object, throw a TypeError exception.
  3. Let Ctr be ? SpeciesConstructor(set, %Set%).
  4. Let thisValues be ? CreateListFromIterable(set).
  5. Let otherValues be ? CreateListFromIterable(iterable).
  6. Let values be a new empty List.
  7. For each element e of thisValues, in List order, do
    1. If SameValueZeroIncludes(values, e) is false, then
      1. Append e as the last element of values.
  8. For each element e of otherValues, in List order, do
    1. If SameValueZeroIncludes(values, e) is false, then
      1. Append e as the last element of values.
  9. Let valuesArray be CreateArrayFromList(values).
  10. Return ? Construct(Ctr, valuesArray).

3Set.prototype.intersection(iterable)

When the intersection method is called with argument iterable, the following steps are taken:

  1. Let set be the this value.
  2. If Type(set) is not Object, throw a TypeError exception.
  3. Let Ctr be ? SpeciesConstructor(set, %Set%).
  4. Let hasCheck be ? Get(set, "has").
  5. If IsCallable(hasCheck) is false, throw a TypeError exception.
  6. Let values be a new empty List.
  7. Let iteratorRecord be ? GetIterator(iterable).
  8. Repeat,
    1. Let next be ? IteratorStep(iteratorRecord).
    2. If next is false, then
      1. Let valuesArray be CreateArrayFromList(values).
      2. Return ? Construct(Ctr, valuesArray).
    3. Let nextValue be ? IteratorValue(next).
    4. If SameValueZeroIncludes(values, nextValue) is false, then
      1. Let has be Call(hasCheck, set, « nextValue »).
      2. If has is an abrupt completion, return ? IteratorClose(iteratorRecord, has).
      3. If has.[[Value]] is true, then
        1. Append nextValue as the last element of values.

4Set.prototype.difference(iterable)

When the difference method is called with argument iterable, the following steps are taken:

  1. Let set be the this value.
  2. If Type(set) is not Object, throw a TypeError exception.
  3. Let Ctr be ? SpeciesConstructor(set, %Set%).
  4. Let iteratorRecord be ? GetIterator(set).
  5. If Type(iterable) is not Object, throw a TypeError exception.
  6. Let otherSet be iterable.
  7. Let hasCheck be ? Get(otherSet, "has").
  8. If IsCallable(hasCheck) is false,
    1. Let otherSet be ? Construct(%Set%, iterable).
    2. Let hasCheck be %SetProto_has%.
  9. Let values be a new empty List.
  10. Repeat,
    1. Let next be ? IteratorStep(iteratorRecord).
    2. If next is false, then
      1. Let valuesArray be CreateArrayFromList(values).
      2. Return ? Construct(Ctr, valuesArray).
    3. Let nextValue be ? IteratorValue(next).
    4. If SameValueZeroIncludes(values, nextValue) is false, then
      1. Let has be Call(hasCheck, otherSet, « nextValue »).
      2. If has is an abrupt completion, return ? IteratorClose(iteratorRecord, has).
      3. If has.[[Value]] is false, then
        1. Append nextValue as the last element of values.

5Set.prototype.symmetricDifference(iterable)

When the symmetricDifference method is called with argument iterable, the following steps are taken:

  1. Let set be the this value.
  2. If Type(set) is not Object, throw a TypeError exception.
  3. Let Ctr be ? SpeciesConstructor(set, %Set%).
  4. Let thisValues be ? CreateListFromIterable(set).
  5. Let otherValues be ? CreateListFromIterable(iterable).
  6. Let values be a new empty List.
  7. For each element e of thisValues, in List order, do
    1. If SameValueZeroIncludes(values, e) is false and SameValueZeroIncludes(otherValues, e) is false, then
      1. Append e as the last element of values.
  8. For each element e of otherValues, in List order, do
    1. If SameValueZeroIncludes(values, e) is false and SameValueZeroIncludes(thisValues, e) is false, then
      1. Append e as the last element of values.
  9. Let valuesArray be CreateArrayFromList(values).
  10. Return ? Construct(Ctr, valuesArray).

6Set.prototype.isSubsetOf(iterable)

When the isSubsetOf method is called with argument iterable, the following steps are taken:

  1. Let set be the this value.
  2. Let iteratorRecord be ? GetIterator(set).
  3. If Type(iterable) is not Object, throw a TypeError exception.
  4. Let otherSet be iterable.
  5. Let hasCheck be ? Get(otherSet, "has").
  6. If IsCallable(hasCheck) is false,
    1. Let otherSet be ? Construct(%Set%, iterable).
    2. Let hasCheck be %SetProto_has%.
  7. Repeat,
    1. Let next be ? IteratorStep(iteratorRecord).
    2. If next is false, return true.
    3. Let nextValue be ? IteratorValue(next).
    4. Let has be Call(hasCheck, otherSet, « nextValue »).
    5. If has is an abrupt completion, return ? IteratorClose(iteratorRecord, has).
    6. If has.[[Value]] is false, return false.

7Set.prototype.isSupersetOf(iterable)

When the isSupersetOf method is called with argument iterable, the following steps are taken:

  1. Let set be the this value.
  2. If Type(set) is not Object, throw a TypeError exception.
  3. Let hasCheck be ? Get(set, "has").
  4. If IsCallable(hasCheck) is false, throw a TypeError exception.
  5. Let iteratorRecord be ? GetIterator(iterable).
  6. Repeat,
    1. Let next be ? IteratorStep(iteratorRecord).
    2. If next is false, return true.
    3. Let nextValue be ? IteratorValue(next).
    4. Let has be Call(hasCheck, set, « nextValue »).
    5. If has is an abrupt completion, return ? IteratorClose(iteratorRecord, has).
    6. If has.[[Value]] is false, return false.

8Set.prototype.isDisjointFrom(iterable)

When the isDisjointFrom method is called with argument iterable, the following steps are taken:

  1. Let set be the this value.
  2. If Type(set) is not Object, throw a TypeError exception.
  3. Let hasCheck be ? Get(set, "has").
  4. If IsCallable(hasCheck) is false, throw a TypeError exception.
  5. Let iteratorRecord be ? GetIterator(iterable).
  6. Repeat,
    1. Let next be ? IteratorStep(iteratorRecord).
    2. If next is false, return true.
    3. Let nextValue be ? IteratorValue(next).
    4. Let has be Call(hasCheck, set, « nextValue »).
    5. If has is an abrupt completion, return ? IteratorClose(iteratorRecord, has).
    6. If has.[[Value]] is true, return false.

9 SameValueZeroIncludes ( list, value )

The abstract operation SameValueZeroIncludes takes two arguments, a List list of ECMAScript language values and an ECMAScript language value value. It performs the following steps:

  1. For each element e of list, do
    1. If e is not empty and SameValueZero(e, value) is true, then
      1. Return true.
  2. Return false.

10 CreateListFromIterable ( iterable )

The abstract operation CreateListFromIterable is used to create a List value whose elements are provided by iterable. It performs the following steps:

  1. Let result be a new empty List.
  2. Let iteratorRecord be ? GetIterator(iterable).
  3. Repeat,
    1. Let next be ? IteratorStep(iteratorRecord).
    2. If next is false, return result.
    3. Let nextValue be ? IteratorValue(next).
    4. Append nextValue as the last element of result.

ACopyright & Software License

Copyright Notice

© 2019 Michał Wadas, Sathya Gunasekaran

Software License

All Software contained in this document ("Software") is protected by copyright and is being made available under the "BSD License", included below. This Software may be subject to third party rights (rights from parties other than Ecma International), including patent rights, and no licenses under such third party rights are granted under this license even if the third party concerned is a member of Ecma International. SEE THE ECMA CODE OF CONDUCT IN PATENT MATTERS AVAILABLE AT https://ecma-international.org/memento/codeofconduct.htm FOR INFORMATION REGARDING THE LICENSING OF PATENT CLAIMS THAT ARE REQUIRED TO IMPLEMENT ECMA INTERNATIONAL STANDARDS.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

  1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
  2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
  3. Neither the name of the authors nor Ecma International may be used to endorse or promote products derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE ECMA INTERNATIONAL "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL ECMA INTERNATIONAL BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.