On Tue, Dec 07, 2004 at 09:50:58AM -0800, Isaac Jones wrote:
My hope is to eventually just have the exposed modules list on there (and available to layered tools) and have it determine the dependencies. Same with the main modules for executables. It would be nice if the exposed modules list were available to the tools, but that's not a requirement.
Another possibility is to have Exposed-Modules in the package description, and a field in the build info listing modules from that list to be excluded from a build on this system.
What I mean is that you can have two files, Setup.description, and yourgenerateddescription.in. The former has the required fields and the later has the build information, then main would be something like this:
main = do e <- doesFileExist "yourgenerateddescription" when (not e) (system "autoconf yourgenerateddescription.in") desc <- readPackageDescription "yourgenerateddescription" defaultMainNoRead desc
How about using optional files as the hooks, something like configure pkg_descr ... = configureExists <- fileExists "configure.lhs" when configureExists $ rawSystem "runhaskell" ["configure.lhs"] buildInfoExists <- fileExists "yourgenerateddescription" buildInfo <- if buildInfoExists then readBuildInfo "yourgenerateddescription" else return (defaultBuildInfo pkg_descr) ... (You'd probably also want some way for configure.lhs to indicate failure.) I'd also like Setup.lhs itself to be optional, defaulting to the simple one, which can be precompiled.
So the only issue here is that you have a bit of a configure step no matter what commands they use. It would indeed be nice to have hooks for the commands. I'm a bit worried about making the Distribution.Simple interface complex, but I wanted to add hooks for "test" and "postinst" anyway. The problem is, do we need all of: {pre,post}{configure,build,install}, test?
There can be different tests before and after installation, too, and the test would need some way of indicating success or failure. I imagine you have a plan to have Hackage plug into an autobuilder so the package list can show what versions of what compilers a package works with -- that would be very useful, not least in flagging abandoned packages.
BTW, I was toying with the idea of using the config file parser from John Goerzen's MissingH in the Cabal, and provide it for Setup.lhs authors to write and parser their own configuration-related files.
I'd be keener to have specified file formats with corresponding parsers in the library. Lengthy Setup.lhs scripts will be a maintainance headache, I think.