[Haskell-cafe] building "encoding" on Windows?

[Andrew Coppin]

Han Joosten wrote:
> The haskell platform should take care of a lot of installation pain,
> specially for the non-technical users.

I note with dismay that there's a proposal to remove OpenGL from HP. 
Assuming this gets approved, that'll be one less library that you can 
use on Windows. I thought the idea of HP was to add new stuff, not 
remove existing stuff...

> A new version is due to be release
> pretty soon (somewhere begin april). It has Mingw and Msys included, and
> also some pre-built binaries like cabal and haddock.

Plain GHC has included Haddock for a while now. It seems to me that 
including the entirity of MinGW and MSYS is overkill, but what do I know 
about the matter? I was however under the impression that to use Unix 
emulators such as these, you have to run everything from a seperate 
shell rather than the usual Windows shell.

> It should be possible
> for a lot of packages to say 'cabal install <package>' at the command prompt
> to get your package up and running. I think that this is pretty cool, and
> most non-technical users should be able to get this to work without a lot of
> pain. 
>   

Having gone through the pain of setting up OpenSUSE and convincing it to 
install GHC, it was quite impressive to use. On Linux, it seems you can 
actually type "cabal install zlib" and reasonably expect it to actually 
work. Typically, it'll crash and say "install zlib-devel". You install 
that, rerun the command, and somehow it knows that you've installed the 
headers and where you've put them, and It Just Works(tm). Which is quite 
impressive.

What isn't impressive is that if you ask to install something, and one 
of its dependencies fails to build, the failure message will get burried 
in amoungst several pages of other stuff. At the end it will say 
something like "package Foo failed to build. The build failure was: exit 
code 1." Yeah, that's really helpful. Fortunately, if you just rebuild, 
it will only try to rebuild the missing dependences, so you can usually 
catch the real error message scroll past (invariably some C headers not 
installed). I also have a personal wish that more tools would make use 
of coloured text output to make it easier to see what's happening in the 
sea of text scrolling past. (We even have a fully portable Haskell 
library for doing this - and it even builds cleanly on Windows!)

My hope is that the more useful C libraries will get added to HP so that 
I can start using them. (E.g., I'd love to be able to do sound synthesis 
using Haskell, but there aren't any libraries for accessing the sound 
hardware...)