| 'use strict'; |
| var $ = require('../internals/export'); |
| var IS_PURE = require('../internals/is-pure'); |
| var anObject = require('../internals/an-object'); |
| var aFunction = require('../internals/a-function'); |
| var getSetIterator = require('../internals/get-set-iterator'); |
| var iterate = require('../internals/iterate'); |
| |
| // `Set.prototype.reduce` method |
| // https://github.com/tc39/proposal-collection-methods |
| $({ target: 'Set', proto: true, real: true, forced: IS_PURE }, { |
| reduce: function reduce(callbackfn /* , initialValue */) { |
| var set = anObject(this); |
| var iterator = getSetIterator(set); |
| var noInitial = arguments.length < 2; |
| var accumulator = noInitial ? undefined : arguments[1]; |
| aFunction(callbackfn); |
| iterate(iterator, function (value) { |
| if (noInitial) { |
| noInitial = false; |
| accumulator = value; |
| } else { |
| accumulator = callbackfn(accumulator, value, value, set); |
| } |
| }, undefined, false, true); |
| if (noInitial) throw TypeError('Reduce of empty set with no initial value'); |
| return accumulator; |
| } |
| }); |