_reduce.js•1.61 kB
var _xwrap = require('./_xwrap');
var bind = require('../bind');
var isArrayLike = require('../isArrayLike');
module.exports = (function() {
function _arrayReduce(xf, acc, list) {
var idx = 0;
var len = list.length;
while (idx < len) {
acc = xf['@@transducer/step'](acc, list[idx]);
if (acc && acc['@@transducer/reduced']) {
acc = acc['@@transducer/value'];
break;
}
idx += 1;
}
return xf['@@transducer/result'](acc);
}
function _iterableReduce(xf, acc, iter) {
var step = iter.next();
while (!step.done) {
acc = xf['@@transducer/step'](acc, step.value);
if (acc && acc['@@transducer/reduced']) {
acc = acc['@@transducer/value'];
break;
}
step = iter.next();
}
return xf['@@transducer/result'](acc);
}
function _methodReduce(xf, acc, obj) {
return xf['@@transducer/result'](obj.reduce(bind(xf['@@transducer/step'], xf), acc));
}
var symIterator = (typeof Symbol !== 'undefined') ? Symbol.iterator : '@@iterator';
return function _reduce(fn, acc, list) {
if (typeof fn === 'function') {
fn = _xwrap(fn);
}
if (isArrayLike(list)) {
return _arrayReduce(fn, acc, list);
}
if (typeof list.reduce === 'function') {
return _methodReduce(fn, acc, list);
}
if (list[symIterator] != null) {
return _iterableReduce(fn, acc, list[symIterator]());
}
if (typeof list.next === 'function') {
return _iterableReduce(fn, acc, list);
}
throw new TypeError('reduce: list must be array or iterable');
};
}());