4 ms·

Functional Programming in JavaScript using LiveScript and prelude.ls

60 points by 0x1997 14y ago

coenhyde 14y ago
This is fantastic! I love that it has currying and composing. I'm going to switch from CoffeeScript to LiveScript.
petitmiam 14y ago
LiveScript is an interesting choice of name. JavaScript was officially called LiveScript back in Netscape Navigator 2.0 beta.
- GeZe 14y ago
  Yes, it's an inside joke for those who know JavaScript well.
chii 14y ago
have you heard of http://roy.brianmckenna.org/ http://roy.brianmckenna.org/ ? Its basically haskell in javascript.
- GeZe 14y ago
  Yes, I am aware - it is an interesting project. However, it's a couple of steps farther away from JavaScript than I would want to work with.
  - pufuwozu 14y ago
    Author of Roy here. Would love to hear more about how/where you think it's too far away from JavaScript. I'm trying to avoid that feeling :) brian@brianmckenna.org (also, I'm writing an untyped typeclassopedia for use in my compiler - I'll be releasing it soon - definitely feel that'd be a complement to prelude.ls)
    - pdelgallego 14y ago
      Hi Brian, I was looking forward to see your presentation in SpainJS next month, but I might not be able to make it. Is there any of your roy talks online or any gentle introduction to roy besides roy.brianmckenna.org?
      - pufuwozu 14y ago
        You can checkout my JSConf talk at: http://brianmckenna.org/files/presentations/jsconf-roy/ http://brianmckenna.org/files/presentations/jsconf-roy/ - hopefully the video will be posted soon I wrote an article about it for IEEE's Internet Computing magazine: http://brianmckenna.org/blog/roy_ieee http://brianmckenna.org/blog/roy_ieee I've also started writing an introduction but it has been shelved while I work on making the typesystem sound. Hopefully I'll see you at SpainJS if you make it :)
    - GeZe 14y ago
      Hi Brian, thanks for creating Roy, it's very cool! I've underlined LiveScript functional features in this blog post, but like JavaScript, LiveScript also supports imperative and object-oriented programming. One could port a JavaScript program to LiveScript with relative ease, as it's just syntax changes (with features added on top). I do not think that would be possible in Roy. For some people that's fine, but for my own projects I would prefer using something that maps more closely to JavaScript.
adrusi 14y ago
while it's a great language, and I was a fan of coco for a while, my experience with coco was that it was like a ghost town and I was one of the only users.
- GeZe 14y ago
  Coco is amazing. To avoid becoming a "ghost town", I have made LiveScript much more compatible with CoffeeScript, easing transitions. I have invested time into making a decent website, and have now composed a couple of blog posts promoting LiveScript. Already several people have written projects in LiveScript: https://github.com/gkz/LiveScript/wiki/Projects-using-LiveScript https://github.com/gkz/LiveScript/wiki/Projects-using-LiveSc... I hope with my continued efforts that the scenario you describe can be avoided.
  - egeozcan 14y ago
    I think what you did is great but a very important missing thing is syntax highlighting for ls files on GitHub. Maybe you can make a pull to their Linguist? https://github.com/github/linguist https://github.com/github/linguist
jhickner 14y ago
I really like the coffeescript + haskell feel. I always miss haskell's '$' for function application and '.' for composition. LiveScript has both (<| and .). Check out the "10 LiveScript one-liners to impress your friends" post. Great stuff: http://gkz.github.com/LiveScript/blog/livescript-one-liners-to-impress-your-friends.html http://gkz.github.com/LiveScript/blog/livescript-one-liners-...
egeozcan 14y ago
I'm a JavaScript fan and I'm impressed. Still feel like a bit overwhelmed with so many new ideas though. By the way, does LiveScript (the name really makes me smile and even giggle) support source maps? see http://www.html5rocks.com/en/tutorials/developertools/sourcemaps/ http://www.html5rocks.com/en/tutorials/developertools/source... for more info
riffraff 14y ago
why use map (-> it.length > x), list map (call \toUpperCase), 'haha' for functions with only one free variable? IMHO it would be prettier to have something like scala's _ map (_.length > x), list map (_.toUpperCase), 'haha' i.e. automatically build a closure when _ is used eithout the need for additional anonymous function syntax
- quarterto 14y ago
  They discussed this, and decided: a) partially-applied operators fills some of the gap, and b) they're far too complicated to implement. https://github.com/gkz/LiveScript/issues/19 https://github.com/gkz/LiveScript/issues/19 https://github.com/taku0/placeholder_syntax_for_coffeescript/blob/master/src/placeholder.coffee https://github.com/taku0/placeholder_syntax_for_coffeescript...
  - riffraff 14y ago
    ah, thanks, I missed partially applied operators. But then, it seems easy to do it with single method calls too, e.g. map (.length) x rather than map (call \length) x does not fit more complex usage, but it's a tiny improvement I'd think
    - GeZe 14y ago
      This is an interesting idea - I will look into it. It does not seem to conflict with the current syntax. Thanks for the suggestion!
- adrusi 14y ago
  I'm not a big fan of scala's _ operator. I find it a poor decision from a language design perspective for _.method(param) to be a function, but for a.method(param) to not be a function (unless of course method returns a function) It also doesn't nest properly
ne0codex 14y ago
Interesting, but I strongly dislike the use of whitespace indentation for new statements/segments of code, it will get tedious when you are nesting multiple blocks of code. And I like it when Xcode highlights the brackets/parenthesis because it's just easier to pick up ( and ) and { and } from a line of text.
- wffurr 14y ago
  If { Your { Code { Is { That { Nested { } } } } } } Then you at not using the functional programming constructs available to you and have poorly decomposed code. Deep nesting is a major code smell.

60 points by 0x1997 14y ago

This is fantastic! I love that it has currying and composing. I'm going to switch from CoffeeScript to LiveScript.

LiveScript is an interesting choice of name. JavaScript was officially called LiveScript back in Netscape Navigator 2.0 beta.

GeZe 14y ago
Yes, it's an inside joke for those who know JavaScript well.

chii 14y ago

have you heard of http://roy.brianmckenna.org/ http://roy.brianmckenna.org/ ? Its basically haskell in javascript.

GeZe 14y ago
Yes, I am aware - it is an interesting project. However, it's a couple of steps farther away from JavaScript than I would want to work with.
- pufuwozu 14y ago
  Author of Roy here. Would love to hear more about how/where you think it's too far away from JavaScript. I'm trying to avoid that feeling :) brian@brianmckenna.org (also, I'm writing an untyped typeclassopedia for use in my compiler - I'll be releasing it soon - definitely feel that'd be a complement to prelude.ls)
  - pdelgallego 14y ago
    Hi Brian, I was looking forward to see your presentation in SpainJS next month, but I might not be able to make it. Is there any of your roy talks online or any gentle introduction to roy besides roy.brianmckenna.org?
    - pufuwozu 14y ago
      You can checkout my JSConf talk at: http://brianmckenna.org/files/presentations/jsconf-roy/ http://brianmckenna.org/files/presentations/jsconf-roy/ - hopefully the video will be posted soon I wrote an article about it for IEEE's Internet Computing magazine: http://brianmckenna.org/blog/roy_ieee http://brianmckenna.org/blog/roy_ieee I've also started writing an introduction but it has been shelved while I work on making the typesystem sound. Hopefully I'll see you at SpainJS if you make it :)
  - GeZe 14y ago
    Hi Brian, thanks for creating Roy, it's very cool! I've underlined LiveScript functional features in this blog post, but like JavaScript, LiveScript also supports imperative and object-oriented programming. One could port a JavaScript program to LiveScript with relative ease, as it's just syntax changes (with features added on top). I do not think that would be possible in Roy. For some people that's fine, but for my own projects I would prefer using something that maps more closely to JavaScript.

adrusi 14y ago

while it's a great language, and I was a fan of coco for a while, my experience with coco was that it was like a ghost town and I was one of the only users.

GeZe 14y ago
Coco is amazing. To avoid becoming a "ghost town", I have made LiveScript much more compatible with CoffeeScript, easing transitions. I have invested time into making a decent website, and have now composed a couple of blog posts promoting LiveScript. Already several people have written projects in LiveScript: https://github.com/gkz/LiveScript/wiki/Projects-using-LiveScript https://github.com/gkz/LiveScript/wiki/Projects-using-LiveSc... I hope with my continued efforts that the scenario you describe can be avoided.
- egeozcan 14y ago
  I think what you did is great but a very important missing thing is syntax highlighting for ls files on GitHub. Maybe you can make a pull to their Linguist? https://github.com/github/linguist https://github.com/github/linguist

jhickner 14y ago

I really like the coffeescript + haskell feel. I always miss haskell's '$' for function application and '.' for composition. LiveScript has both (<| and .). Check out the "10 LiveScript one-liners to impress your friends" post. Great stuff: http://gkz.github.com/LiveScript/blog/livescript-one-liners-to-impress-your-friends.html http://gkz.github.com/LiveScript/blog/livescript-one-liners-...

egeozcan 14y ago

I'm a JavaScript fan and I'm impressed. Still feel like a bit overwhelmed with so many new ideas though. By the way, does LiveScript (the name really makes me smile and even giggle) support source maps? see http://www.html5rocks.com/en/tutorials/developertools/sourcemaps/ http://www.html5rocks.com/en/tutorials/developertools/source... for more info

riffraff 14y ago

why use map (-> it.length > x), list map (call \toUpperCase), 'haha' for functions with only one free variable? IMHO it would be prettier to have something like scala's _ map (_.length > x), list map (_.toUpperCase), 'haha' i.e. automatically build a closure when _ is used eithout the need for additional anonymous function syntax

quarterto 14y ago
They discussed this, and decided: a) partially-applied operators fills some of the gap, and b) they're far too complicated to implement. https://github.com/gkz/LiveScript/issues/19 https://github.com/gkz/LiveScript/issues/19 https://github.com/taku0/placeholder_syntax_for_coffeescript/blob/master/src/placeholder.coffee https://github.com/taku0/placeholder_syntax_for_coffeescript...
- riffraff 14y ago
  ah, thanks, I missed partially applied operators. But then, it seems easy to do it with single method calls too, e.g. map (.length) x rather than map (call \length) x does not fit more complex usage, but it's a tiny improvement I'd think
  - GeZe 14y ago
    This is an interesting idea - I will look into it. It does not seem to conflict with the current syntax. Thanks for the suggestion!
adrusi 14y ago
I'm not a big fan of scala's _ operator. I find it a poor decision from a language design perspective for _.method(param) to be a function, but for a.method(param) to not be a function (unless of course method returns a function) It also doesn't nest properly

ne0codex 14y ago

Interesting, but I strongly dislike the use of whitespace indentation for new statements/segments of code, it will get tedious when you are nesting multiple blocks of code. And I like it when Xcode highlights the brackets/parenthesis because it's just easier to pick up ( and ) and { and } from a line of text.

wffurr 14y ago
If { Your { Code { Is { That { Nested { } } } } } } Then you at not using the functional programming constructs available to you and have poorly decomposed code. Deep nesting is a major code smell.