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4 years ago
'use strict';
// https://github.com/tc39/proposal-iterator-helpers
var aFunction = require('../internals/a-function');
var anObject = require('../internals/an-object');
var getBuiltIn = require('../internals/get-built-in');
var Promise = getBuiltIn('Promise');
var push = [].push;
var createMethod = function (TYPE) {
var IS_TO_ARRAY = TYPE == 0;
var IS_FOR_EACH = TYPE == 1;
var IS_EVERY = TYPE == 2;
var IS_SOME = TYPE == 3;
return function (iterator, fn) {
anObject(iterator);
var next = aFunction(iterator.next);
var array = IS_TO_ARRAY ? [] : undefined;
if (!IS_TO_ARRAY) aFunction(fn);
return new Promise(function (resolve, reject) {
var loop = function () {
try {
Promise.resolve(anObject(next.call(iterator))).then(function (step) {
try {
if (anObject(step).done) {
resolve(IS_TO_ARRAY ? array : IS_SOME ? false : IS_EVERY || undefined);
} else {
var value = step.value;
if (IS_TO_ARRAY) {
push.call(array, value);
loop();
} else {
Promise.resolve(fn(value)).then(function (result) {
if (IS_FOR_EACH) {
loop();
} else if (IS_EVERY) {
result ? loop() : resolve(false);
} else {
result ? resolve(IS_SOME || value) : loop();
}
}, reject);
}
}
} catch (err) { reject(err); }
}, reject);
} catch (error) { reject(error); }
};
loop();
});
};
};
module.exports = {
toArray: createMethod(0),
forEach: createMethod(1),
every: createMethod(2),
some: createMethod(3),
find: createMethod(4)
};