Re: [arch-haskell] Thoughts on Procedure

14 Oct 2010

      remyoudompheng:
...
On 2010/10/14 Don Stewart  wrote:
...
You can use cabal-install to do consistency checks, as described here:
   http://www.well-typed.com/blog/24
[...]
Indicating that those are inconsistent. You could take the list of
things in AUR, with version numbers, and ask cabal install if they're
consistent (and then, when they're not, iterate, removing inconsistent
packages).
That's certainly a good idea, but we would have to encode the package
name in the PKGBUILD to retrieve it easily. The best option would be
to have cabal-install as a library so that we could access it from
Haskell. I don't want to use IOs for something that should be a pure
function.
Well, its not the end of the world, and it is a pure function over the parsed
set of PKGBUILDs.

The Haskell/Cabal package name for a given Arch package is computed from
the Hackage URL in the PKGBUILD, like so:

    import Distribution.ArchLinux.AUR
    import Distribution.ArchLinux.PkgBuild
    import System.Environment
    import System.FilePath

    main = do
        [p] <- getArgs
        k <- package p

        case k of
             (Right aur, _) | not (null (packageURL aur))  -> do
                                     putStrLn $ takeFileName (packageURL aur) -- haskell package name
             _ -> putStrLn $ "Package "++show p++" doesn't have an associated PKGBUILD"

An example:

    $ ./get-hackage-name.hs haskell-haxml
    HaXml

-- Don