37 lines
761 B
Plaintext
37 lines
761 B
Plaintext
|
function __reduce(arr, memo, iteratee, cb) {
|
||
|
|
if (typeof cb !== 'function') {
|
||
|
|
if (typeof memo === 'function' && typeof iteratee === 'function') {
|
||
|
|
cb = iteratee;
|
||
|
|
iteratee = memo;
|
||
|
|
memo = [];
|
||
|
|
} else {
|
||
|
|
throw new TypeError('expected callback to be a function');
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
if (!Array.isArray(arr)) {
|
||
|
|
cb(new TypeError('expected an array'));
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (typeof iteratee !== 'function') {
|
||
|
|
cb(new TypeError('expected iteratee to be a function'));
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
|
||
|
|
(function next(i, acc) {
|
||
|
|
if (i === arr.length) {
|
||
|
|
cb(null, acc);
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
|
||
|
|
iteratee(acc, arr[i], function(err, val) {
|
||
|
|
if (err) {
|
||
|
|
cb(err);
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
next(i + 1, val);
|
||
|
|
});
|
||
|
|
})(0, memo);
|
||
|
|
};
|