5 ms·

WebAssembly back end merged into GHC

123 points by dfee 4y ago

siwatanejo 4y ago
GHC -> Haskell
- rob74 4y ago
  Yeah, that was the first question on my mind too: "WTF is GHC?". A quick Google search reveals that it's the Glasgow Haskell Compiler. Maybe it makes sense to expand that in the title?
  - redactyl 4y ago
    Haskell is a language standard, and GHC is an implementation of that standard. It may be the only one (not sure the status of Hugs, another implementation), but that's the difference, I believe.
- kajika91 4y ago
  Thanks, same here, it rings a bell but I was unsure.
Laaas 4y ago
Is it just me or does it seem nonsensical that TH splices are compiled to WASM then executed with a WASM interpreter rather than just being interpreted natively by GHC like done with GHCi? Would also fix the weird situation with running git inside splices not working.
- whateveracct 4y ago
  In general, you must run TH on the target platform for it to be correct. Otherwise, you may generate code that only works on your host (it isn't impossible for TH output to be platform-specific especially since it can do IO)
  - marcosdumay 4y ago
    Well, now the standard can change so it always runs as WASM, and completely fix the issue.
    - whateveracct 4y ago
      But sometimes it might want to run on the host still (e.g. there are tools out there that generate C bindings that use platform-specific things like sizes and alignments) If we had pure TH, then at least that could run in wasm. That would be nice. But idk - I cross-compile Haskell heavily in my free time and I don't mind the external interpreter stuff.
      - marcosdumay 4y ago
        > If we had pure TH, then at least that could run in wasm. That would be nice. IMO, ideally, pure TH wold be completely platform independent. But running in a standardized VM is a close second place. Anyway, I never realized those bidings were created with TH.
        whateveracct 4y ago
        `inline-c` is the main example I can think of
- vmchale 4y ago
  Yes it's quite an unfortunate situation. Edward Z Yang has a canonical post on this: http://blog.ezyang.com/2016/07/what-template-haskell-gets-wrong-and-racket-gets-right/ http://blog.ezyang.com/2016/07/what-template-haskell-gets-wr...
osener 4y ago
This is pretty cool. If I wanted to compile some old Haskell app, that was built with GHCJS, to WebAssembly should I use this unreleased branch of GHC or go for (seemingly) batteries included Asterius?

123 points by dfee 4y ago

siwatanejo 4y ago

GHC -> Haskell

rob74 4y ago
Yeah, that was the first question on my mind too: "WTF is GHC?". A quick Google search reveals that it's the Glasgow Haskell Compiler. Maybe it makes sense to expand that in the title?
- redactyl 4y ago
  Haskell is a language standard, and GHC is an implementation of that standard. It may be the only one (not sure the status of Hugs, another implementation), but that's the difference, I believe.
kajika91 4y ago
Thanks, same here, it rings a bell but I was unsure.

Laaas 4y ago

Is it just me or does it seem nonsensical that TH splices are compiled to WASM then executed with a WASM interpreter rather than just being interpreted natively by GHC like done with GHCi? Would also fix the weird situation with running git inside splices not working.

whateveracct 4y ago
In general, you must run TH on the target platform for it to be correct. Otherwise, you may generate code that only works on your host (it isn't impossible for TH output to be platform-specific especially since it can do IO)
- marcosdumay 4y ago
  Well, now the standard can change so it always runs as WASM, and completely fix the issue.
  - whateveracct 4y ago
    But sometimes it might want to run on the host still (e.g. there are tools out there that generate C bindings that use platform-specific things like sizes and alignments) If we had pure TH, then at least that could run in wasm. That would be nice. But idk - I cross-compile Haskell heavily in my free time and I don't mind the external interpreter stuff.
    - marcosdumay 4y ago
      > If we had pure TH, then at least that could run in wasm. That would be nice. IMO, ideally, pure TH wold be completely platform independent. But running in a standardized VM is a close second place. Anyway, I never realized those bidings were created with TH.
      - whateveracct 4y ago
        `inline-c` is the main example I can think of
vmchale 4y ago
Yes it's quite an unfortunate situation. Edward Z Yang has a canonical post on this: http://blog.ezyang.com/2016/07/what-template-haskell-gets-wrong-and-racket-gets-right/ http://blog.ezyang.com/2016/07/what-template-haskell-gets-wr...

osener 4y ago

This is pretty cool. If I wanted to compile some old Haskell app, that was built with GHCJS, to WebAssembly should I use this unreleased branch of GHC or go for (seemingly) batteries included Asterius?