It's an explicit Haskell 98 design choice http://haskell.org/onlinereport/modules.html "5.6.2 Shadowing Prelude Names The rules about the Prelude have been cast so that it is possible to use Prelude names for nonstandard purposes; however, every module that does so must have an import declaration that makes this nonstandard usage explicit." It's a decision one could debate, but it was an explicit choice. Simon | -----Original Message----- | From: haskell-cafe-bounces@haskell.org [mailto:haskell-cafe-bounces@haskell.org] On Behalf Of Lyle | Kopnicky | Sent: 12 August 2004 20:23 | To: Haskell Cafe | Subject: [Haskell-cafe] Hiding functions | | Hi all, | | I'm working on a program that uses my own brand of exceptions, and I | created two functions called 'throw' and 'catch'. In order for this to | work, I hide the Prelude 'catch' in my module, called 'Cont.hs'. Thus: | | module Cont where | import Prelude hiding (catch) | ... | throw = ... | catch = ... | | This works hunky-dory until I create another file that imports Cont. I | get a conflict when I use 'catch', so I have to hide the Prelude one again: | | import Prelude hiding (catch) | import Cont | ... | ... throw ... | ... catch ... | | So I'm a bit annoyed by this 'propagation' of hiding clauses. Then I | created a new file, that redefined throw: | | module ResumableExceptions where | import Cont hiding (throw) | import qualified Cont (throw) | ... | throw = ... Cont.throw ... | | Finally, I created a file using ResumableExceptions: | | import Cont hiding (throw) | import ResumableExceptions | ... | ... throw ... | | If I wanted to also use 'catch' I'd have to hide that from the Prelude | as well. | | I can't use type classes to solve this problem, because the types of the | two 'throw' functions are different. | | Perhaps I should just make up new names for these things, eh? But there | might be code that uses 'throw' and doesn't really care which one is | used, and it would be nice to just modify the import line and be done | with it. | | Any opinions? | | Thanks, | Lyle | _______________________________________________ | Haskell-Cafe mailing list | Haskell-Cafe@haskell.org | http://www.haskell.org/mailman/listinfo/haskell-cafe