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'use strict';
// https://github.com/tc39/proposal-iterator-helpers
var $ = require('../internals/export');
var iterate = require('../internals/iterate');
var aFunction = require('../internals/a-function');
var anObject = require('../internals/an-object');
$({ target: 'Iterator', proto: true, real: true }, {
reduce: function reduce(reducer /* , initialValue */) {
anObject(this);
aFunction(reducer);
var noInitial = arguments.length < 2;
var accumulator = noInitial ? undefined : arguments[1];
iterate(this, function (value) {
if (noInitial) {
noInitial = false;
accumulator = value;
} else {
accumulator = reducer(accumulator, value);
}
}, { IS_ITERATOR: true });
if (noInitial) throw TypeError('Reduce of empty iterator with no initial value');
return accumulator;
}
});
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