Implement arrow functions in v8

[feld]

Do we just link to random commits now? I have no idea what arrow functions are or why it would even matter to half the people who visit this site.

edit: after following 4 links I finally found the bug report about it

https://code.google.com/p/v8/issues/detail?id=2700

[bsimpson]

Arrow functions are one of the improvements from JS Harmony (which was ratified last night).

This commit moves them from "behind the experimental flag" to "shipping by default" in Chromium. It's a pretty big deal to people who write JS for a living.

[towelguy]

They are a compact way to write anonymous functions in Javascript, so instead of

    var square = function (a) { return a * a;}

You can write:

    var square = a => a * a;

[JeremyBanks]

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Refe...

[teraflop]

Your link goes to the same page as this post. Was it changed at some point?

[rubiquity]

Then it seems like the perfect opportunity for you to learn something new and stretch your mind a little.

[realusername]

I'm glad it's finally arriving, it been working in Firefox for quite a long time and I'm happy to see v8 implementing this ! Arrow functions are so much nicer to read and use.

[eueueu]

  a=>b<=7
  a>=b<=7

Can you not see the typos possible with this? The less characters you use for something, the more error prone. There's a reason we don't write in regular expression syntax.

Maybe I'm just getting old!

[malandrew]

Do the stack traces for native arrow functions show up in the stack trace as anonymous functions or is only the parent function registered in the stack trace.

[davexunit]

Now read the blog post about it! Andy Wingo is a great compiler hacker and he writes about a lot of things that he works on. http://wingolog.org/archives/2015/06/18/arrow-functions-comi...

[malandrew]

Totally agree. Wingolog is an amazing blog and anyone curious about compilers and v8 in general should check it out.

[nawitus]

Hmm, I get a syntax error from the puzzle in Firefox.

[malandrew]

Anyone have any idea when destructuring assignment is going to make it into v8?

That is one of the features my colleagues most cite as justification for using babel.js (I wouldn't mind destructuring assigment either). I would love to be able to avoid transpilation since it adds overhead from making out our toolchain more complex and makes debugging more difficult because stack traces and line numbers don't necessarily match up.

[bnoordhuis]

It's in the works: https://code.google.com/p/v8/issues/detail?id=811

You can tell by the number of CLs that a lot of work has been done already but there are a few more still in progress. It's probably still a few weeks out.

Disclaimer: I don't speak for the V8 team, I'm just an interested onlooker.

[cozuya]

On the front end you can get babel to work with sourcemaps fairly easily depending on what build tool you use.

[awalGarg]

It has been reverted[1] now. History repeats itself.

[1] - https://code.google.com/p/v8/issues/detail?id=2700#c47

[z3t4]

If you use an anonymous function instead of a named function you'll probably end up writing a comment to clarify ... :P

Sometimes the code explains itself though!?

  allowed = members.filter(member => member.age >= ageLimit);