29 lines
821 B
JavaScript
29 lines
821 B
JavaScript
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var aFunction = require('./_a-function');
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var toObject = require('./_to-object');
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var IObject = require('./_iobject');
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var toLength = require('./_to-length');
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module.exports = function (that, callbackfn, aLen, memo, isRight) {
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aFunction(callbackfn);
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var O = toObject(that);
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var self = IObject(O);
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var length = toLength(O.length);
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var index = isRight ? length - 1 : 0;
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var i = isRight ? -1 : 1;
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if (aLen < 2) for (;;) {
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if (index in self) {
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memo = self[index];
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index += i;
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break;
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}
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index += i;
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if (isRight ? index < 0 : length <= index) {
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throw TypeError('Reduce of empty array with no initial value');
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}
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}
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for (;isRight ? index >= 0 : length > index; index += i) if (index in self) {
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memo = callbackfn(memo, self[index], index, O);
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}
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return memo;
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};
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