On Mon, 21 Mar 2005 22:06:25 -0500 (Eastern Standard Time), S. Alexander Jacobson <[EMAIL PROTECTED]> wrote: > Lemmih, > > The current Haskell/Cabal module and packaging system is substantially > annoying for the typical non-sysadmin end-user. In particular, if > they move their code to another machine they have to do a bunch of > different administrivia including: > > 1. knowing the source package for each module used in their code > even if they didn't insall the packages in the first place i.e. > import Foo.Bar just worked on my development machine.
I'm not sure I completely understand what you're saying but knowing the exact URL for every single module import seems more of a hassle than installing a few packages. You could perhaps even make a shell script containing 'cabal-get install package1 package2 ...'. > 2. knowing the current location of those packages even if they > didn't obtain them for installation on the original machine > where they used them and aren't on the mailing list for them. I assume you meant something like "The developer don't know where to find the packages". The location of the packages is irrelevant to the developer since it's handled by Cabal/Hackage. > 3. going through the hassle of doing a "cabal-get install" for each > of them once they have figured it all out. See the above mentioned shell script or cabalize your software. > I'd rather have a system that takes care of 1-3 for me and just > reports errors if particular modules are irretrievable. > > That being said, Cabal definitely solves a lot of problems that my > original proposal left unaddressed (e.g. producing executables needed > to build modules, handling C code, versioning?). Perhaps the correct > answer is to import Cabal packages rather than haskell source e.g. > > import http://package.org/package-1.0.cabal#Foo.Bar as Baz > import http://package.org/package-2.0.cabal#Foo.Bar as Baz2 > --note use of HTTP fragment identifier for module name Requiring Haskell implementations to honor this would be very bad, IMHO. A preprocessor which looks for package pragmas ({- USE somepackage -} perhaps) and install those packages via Cabal would be way easier to hack. But then again, a small script to fetch the packages or a .cabal file would be even simpler. > And a big bonus here is we get a simple solution to the problem of > Haskell's global module namespace. There was a problem with module name spaces? Wouldn't there only be a problem if two packages used the same module name for different functionality? > Now module namespace is local to > individual packages. > > If cabal also has a "cabal-put package MyPackage http://myhost.com/dir"; > then we have a really simple and beautiful system for sharing > libraries over the Internet as well! This is essentially what Hackage does. > If the change of import syntax is blessed by the powers that be, would > it be hard to adapt Cabal to work like this? Extending the Haskell syntax to include something which could easily be handled by a preprocessor would be inadvisable. > -Alex- > > ______________________________________________________________ > S. Alexander Jacobson tel:917-770-6565 http://alexjacobson.com > -- Friendly, Lemmih _______________________________________________ Haskell mailing list [email protected] http://www.haskell.org/mailman/listinfo/haskell
