Re: [Haskell-cafe] First go at reactive programming

Thanks for the TypeCompose>=0.3 tip. I've fixed my local Reactive.cabal and will push at some point. Oh yeay -- I'd forgotten about the "deriving" change in 6.8 vs 6.6. Urg. I didn't realize that 'forever' isn't in 6.2. You can use the 6.8def: -- | @'forever' act@ repeats the action infinitely. forever :: (Monad m) => m a -> m () forever a = a >> forever a I'm wondering how hard to try to get these libs to work with both 6.6 and 6.8. My hope has been that people will switch to 6.8, but perhaps there are obstacles I don't know about. Is there something that keeps you from upgrading? - Conal On Jan 19, 2008 6:14 AM, Steve Lihn wrote:

Reactive-0.3 seems to have a dependency on TypeCompose-0.3. Earlier version does not work (for lack of Data.Pair). This probably should be specified in Cabal file.

I aslo fixed all the LANGUAGE problems and now encountered the following error in TypeCompose:

[4 of 9] Compiling Control.Compose ( src/Control/Compose.hs, dist/build/Control/Compose.o ) src/Control/Compose.hs:561:0: parse error on input `deriving'

I tried to restored the commented out "deriving Monoid" and got pass that. Not sure if that is right though. Back to reactive-0.3, I encountered:

src/Data/Future.hs:60:27: Module `Control.Monad' does not export `forever'

Forever is in the latest library, but not in my GHC 6.6. I am not sure how to get this fixed. Any suggestion?

http://www.haskell.org/ghc/docs/latest/html/libraries/base/Control-Monad.htm...

Steve

On Jan 19, 2008 1:31 AM, Conal Elliott wrote:

...

Hi Steve,

Thanks for letting me know about the LANGUAGE problem. Yes, I used 6.8-friendly (6.6-unfriendly) LANGUAGE pragmas. In retrospect, probably not such a great idea, since there seem to be many folks still on 6.6.

I just changed the sources (commenting out the LANGUAGE pragmas and inserting -fglasgow-exts pragmas), darcs-pushed, and put a new version ( 0.3) on hackage. Please give it another try.

Cheers, - Conal

On Jan 18, 2008 7:58 PM, Steve Lihn wrote:

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Tried to install reactive-0.2 on GHC-6.6, but failed.

Building reactive-0.2... src/Data/Reactive.hs:1:13: cannot parse LANGUAGE pragma

Is the package for GHC 6.8? Is there an older version (0.0?) for GHC 6.6 that I can play with your example? (Or advise how to hack that file to get it work on 6.6)

Thanks, Steve