Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

Make iterator more prone to JIT optimizations #1247

Merged
merged 1 commit into from
Jul 21, 2016
Merged

Make iterator more prone to JIT optimizations #1247

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
51 changes: 29 additions & 22 deletions lib/internal/iterator.js
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -2,33 +2,40 @@ import isArrayLike from 'lodash/isArrayLike';
import getIterator from './getIterator';
import keys from 'lodash/keys';

export default function iterator(coll) {
function createArrayIterator(coll) {
var i = -1;
var len;
if (isArrayLike(coll)) {
len = coll.length;
return function next() {
i++;
return i < len ? {value: coll[i], key: i} : null;
};
var len = coll.length;
return function next() {
return ++i < len ? {value: coll[i], key: i} : null;
}
}

var iterate = getIterator(coll);
if (iterate) {
return function next() {
var item = iterate.next();
if (item.done)
return null;
i++;
return {value: item.value, key: i};
};
function createES2015Iterator(iterator) {
var i = -1;
return function next() {
var item = iterator.next();
if (item.done)
return null;
i++;
return {value: item.value, key: i};
}
}

var okeys = keys(coll);
len = okeys.length;
function createObjectIterator(obj) {
var okeys = keys(obj);
var i = -1;
var len = okeys.length;
return function next() {
i++;
var key = okeys[i];
return i < len ? {value: coll[key], key: key} : null;
var key = okeys[++i];
return i < len ? {value: obj[key], key: key} : null;
};
}

export default function iterator(coll) {
if (isArrayLike(coll)) {
return createArrayIterator(coll);
}

var iterator = getIterator(coll);
return iterator ? createES2015Iterator(iterator) : createObjectIterator(coll);
}