47 lines
1.5 KiB
JavaScript
47 lines
1.5 KiB
JavaScript
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'use strict';
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var $ = require('../internals/export');
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var anObject = require('../internals/an-object');
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var call = require('../internals/function-call');
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var createIteratorProxy = require('../internals/iterator-create-proxy');
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var getIteratorDirect = require('../internals/get-iterator-direct');
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var iteratorClose = require('../internals/iterator-close');
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var uncurryThis = require('../internals/function-uncurry-this');
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var $RangeError = RangeError;
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var push = uncurryThis([].push);
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var slice = uncurryThis([].slice);
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var IteratorProxy = createIteratorProxy(function () {
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var iterator = this.iterator;
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var next = this.next;
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var buffer = this.buffer;
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var windowSize = this.windowSize;
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var result, done;
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while (true) {
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result = anObject(call(next, iterator));
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done = this.done = !!result.done;
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if (done) return;
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push(buffer, result.value);
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if (buffer.length === windowSize) {
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this.buffer = slice(buffer, 1);
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return buffer;
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}
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}
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});
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// `Iterator.prototype.windows` method
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// https://github.com/tc39/proposal-iterator-chunking
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$({ target: 'Iterator', proto: true, real: true, forced: true }, {
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windows: function windows(windowSize) {
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var O = anObject(this);
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if (typeof windowSize != 'number' || !windowSize || windowSize >>> 0 !== windowSize) {
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return iteratorClose(O, 'throw', new $RangeError('windowSize must be integer in [1, 2^32-1]'));
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}
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return new IteratorProxy(getIteratorDirect(O), {
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windowSize: windowSize,
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buffer: []
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});
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}
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});
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