4 ms·

Hi. I'm one of the engineers who has worked on this so if anyone has any specific questions I can help answer and/or get someone to answer. As said by @nbm, we

by lbrandy 12y ago

Hi. I'm one of the engineers who has worked on this so if anyone has any specific questions I can help answer and/or get someone to answer. As said by @nbm, we also have a blog post up: https://code.facebook.com/posts/302060973291128/open-sourcing-haxl-a-library-for-haskell/ https://code.facebook.com/posts/302060973291128/open-sourcin....

Igglyboo 12y ago
I had no idea you guys used Haskell at FB. Other than Haxl, what are your main use cases for Haskell?
- simonmar 12y ago
  Haxl is the only major project at FB using Haskell right now, but who knows where this will lead?
evmar 12y ago
Have you replaced all use of FXL with Haxl? Or are both languages supported? In the latter case, what is the relative proportion of each in the live codebase? (I appreciate that migrating code that already works to a new language often just introduces bugs for no gain, so please don't take my questions as trying to dig up dirt or anything. I'm genuinely just curious.)
- evincarofautumn 12y ago
  We are still in the process of migrating from FXL to Haxl, and there is too much FXL code to translate manually, so at the moment we are treating FXL as the source of truth, compiling the FXL codebase to Haskell, and running both concurrently to verify correctness.
- deleted 12y ago
  [deleted]
awda 12y ago
Why Haskell?
- lbrandy 12y ago
  Ah, my favorite question. We previously had a custom DSL and it outgrew it's DSL-ness. The DSL was really good at one thing (implicit concurrency and scheduling io), and bad at everything else (cpu, memory, debugging, tooling). The predecessor was wildly successful and created new problems. Once all those secondary concerns became first order, we didn't want to start building all this ecosystem stuff for our homemade DSL. We needed to go from DSL to, ya know, an L. So the question is which... If you understand the central idea of Haxl, I don't know of any other language that would let you do what Haxl in Haskell does. The built in language support for building DSLs (hijacking the operators including applicative/monadic operations) -really- shines in this case. I would -love- to see haxl-like implicit concurrency in other languages that feel as natural and concise. Consider that a challenge. I thought about trying to do it in C++ for edification/pedagogical purposes but it's an absolutely brutal mess of templates and hackery. There may be a better way, though.
  - lukasm 12y ago
    How about Scala?
    - coolsunglasses 12y ago
      Anybody that's made a serious go of FP in Scala (applicative, monad, etc) has found that it's not worth the hassle. It fights you the whole way.
      - tormeh 12y ago
        Scalaz?
        coolsunglasses 12y ago
        I hang out with the Scalazzi and authors of FP in Scala on IRC. Most of them, including the original creator, would rather write Haskell and some are doing just that.
deleted 12y ago
[deleted]
HannibalLecter 12y ago
Will you comment as to whether FB has developed something superior to this or not?

by lbrandy 12y ago

Igglyboo 12y ago

I had no idea you guys used Haskell at FB. Other than Haxl, what are your main use cases for Haskell?

simonmar 12y ago
Haxl is the only major project at FB using Haskell right now, but who knows where this will lead?

evmar 12y ago

Have you replaced all use of FXL with Haxl? Or are both languages supported? In the latter case, what is the relative proportion of each in the live codebase? (I appreciate that migrating code that already works to a new language often just introduces bugs for no gain, so please don't take my questions as trying to dig up dirt or anything. I'm genuinely just curious.)

evincarofautumn 12y ago
We are still in the process of migrating from FXL to Haxl, and there is too much FXL code to translate manually, so at the moment we are treating FXL as the source of truth, compiling the FXL codebase to Haskell, and running both concurrently to verify correctness.
deleted 12y ago
[deleted]

awda 12y ago

Why Haskell?

lbrandy 12y ago
Ah, my favorite question. We previously had a custom DSL and it outgrew it's DSL-ness. The DSL was really good at one thing (implicit concurrency and scheduling io), and bad at everything else (cpu, memory, debugging, tooling). The predecessor was wildly successful and created new problems. Once all those secondary concerns became first order, we didn't want to start building all this ecosystem stuff for our homemade DSL. We needed to go from DSL to, ya know, an L. So the question is which... If you understand the central idea of Haxl, I don't know of any other language that would let you do what Haxl in Haskell does. The built in language support for building DSLs (hijacking the operators including applicative/monadic operations) -really- shines in this case. I would -love- to see haxl-like implicit concurrency in other languages that feel as natural and concise. Consider that a challenge. I thought about trying to do it in C++ for edification/pedagogical purposes but it's an absolutely brutal mess of templates and hackery. There may be a better way, though.
- lukasm 12y ago
  How about Scala?
  - coolsunglasses 12y ago
    Anybody that's made a serious go of FP in Scala (applicative, monad, etc) has found that it's not worth the hassle. It fights you the whole way.
    - tormeh 12y ago
      Scalaz?
      - coolsunglasses 12y ago
        I hang out with the Scalazzi and authors of FP in Scala on IRC. Most of them, including the original creator, would rather write Haskell and some are doing just that.

deleted 12y ago

[deleted]

HannibalLecter 12y ago

Will you comment as to whether FB has developed something superior to this or not?