debian-mirror-gitlab/core-js/internals/iterate.js
2019-10-31 01:37:42 +05:30

43 lines
1.6 KiB
JavaScript

var anObject = require('../internals/an-object');
var isArrayIteratorMethod = require('../internals/is-array-iterator-method');
var toLength = require('../internals/to-length');
var bind = require('../internals/bind-context');
var getIteratorMethod = require('../internals/get-iterator-method');
var callWithSafeIterationClosing = require('../internals/call-with-safe-iteration-closing');
var Result = function (stopped, result) {
this.stopped = stopped;
this.result = result;
};
var iterate = module.exports = function (iterable, fn, that, AS_ENTRIES, IS_ITERATOR) {
var boundFunction = bind(fn, that, AS_ENTRIES ? 2 : 1);
var iterator, iterFn, index, length, result, next, step;
if (IS_ITERATOR) {
iterator = iterable;
} else {
iterFn = getIteratorMethod(iterable);
if (typeof iterFn != 'function') throw TypeError('Target is not iterable');
// optimisation for array iterators
if (isArrayIteratorMethod(iterFn)) {
for (index = 0, length = toLength(iterable.length); length > index; index++) {
result = AS_ENTRIES
? boundFunction(anObject(step = iterable[index])[0], step[1])
: boundFunction(iterable[index]);
if (result && result instanceof Result) return result;
} return new Result(false);
}
iterator = iterFn.call(iterable);
}
next = iterator.next;
while (!(step = next.call(iterator)).done) {
result = callWithSafeIterationClosing(iterator, boundFunction, step.value, AS_ENTRIES);
if (typeof result == 'object' && result && result instanceof Result) return result;
} return new Result(false);
};
iterate.stop = function (result) {
return new Result(true, result);
};