https://github.com/janhancic/fasterforeach.shim

A hack to see if I can make a faster forEach shim.
https://github.com/janhancic/fasterforeach.shim

Last synced: 22 days ago
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A hack to see if I can make a faster forEach shim.

• Host: GitHub
• URL: https://github.com/janhancic/fasterforeach.shim
• Owner: janhancic
• License: mit
• Created: 2014-02-02T02:03:10.000Z (almost 11 years ago)
• Default Branch: master
• Last Pushed: 2014-02-15T13:53:17.000Z (over 10 years ago)
• Last Synced: 2024-04-14T19:15:47.268Z (7 months ago)
• Language: JavaScript
• Homepage: http://hancic.info/creating-a-faster-foreach-shim
• Size: 148 KB
• Stars: 2
• Watchers: 2
• Forks: 0
• Open Issues: 1
• Metadata Files:
  • Readme: README.md
  • License: LICENSE.md

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README

        
# fasterForEach

A hack to see if I can make a faster forEach shim for IE8.

## About

This is a hack that adds support for `Array#forEach` to IE8 but in a different way than the [ES5 shim](https://github.com/es-shims/es5-shim).

This basically rewrites the item processor (callback you pass into forEach) into a regular `for` loop and executes that (as oposed to executing the callback on each iteration). The result is that instead of `1 + n` function invocations that you get with native or shimed `forEach` you get only two function invocations.

I created two nearly identical versions, the only difference is how the rewriten code gets executed. One uses `eval` and the other uses `new Function()`.

Testing shows that both versions are faster than the ES5 shim. However I only have access to a VM from [modern.ie](http://modern.ie) running on a Macbook Air. But please visit this [jsPerf test page](http://jsperf.com/faster-foreach-shim) and give it a spin so I can collect more data.

## Is it usable?

I haven't tested this in any real project, but in theory I don't see why it couldn't be used.

## License

Licensed under MIT. See `LICENSE.md` file for details.