On Sat, Oct 30, 2010 at 7:38 AM, Isaac Dupree
On 10/29/10 20:19, Bas van Dijk wrote:
I'm not sure this is in rc2 since I'm using the latest ghc-HEAD (7.1.20101029).
In ghc< 7 you needed to import symbols like fromInteger, (>>=) and fail when you used them indirectly. For example when using integer literals or do-notation.
I noticed that in my ghc-HEAD this isn't needed anymore:
{-# OPTIONS_GHC -Wall #-} {-# LANGUAGE NoImplicitPrelude #-}
Yes, in HEAD only, NoImplicitPrelude no longer implies RebindableSyntax.
Thanks, for the explanation.
http://darcs.haskell.org/cgi-bin/darcsweb.cgi?r=ghc;a=darcs_commitdiff;h=201...
import Control.Monad ( return ) import System.IO ( IO ) import Data.Int
-- Only needed for ghc< 7. -- In fact, the following gives a redundancy warning in ghc-7: import Control.Monad ( (>>=), fail ) import Prelude ( fromInteger )
However, a redundancy warning sounds wrong (or at least confusing). An "unused import" warning seems more appropriate to me, although it's a bit of a grey area. If you remove LANGUAGE NoImplicitPrelude from the module, what warning do you get? (maybe test that in HEAD as well as 6.12 or so)
Without NoImplicitPrelude: $ /usr/bin/ghc-6.12.3 --make GHC7.hs -fforce-recomp [1 of 1] Compiling Main ( GHC7.hs, GHC7.o ) GHC7.hs:9:0: Warning: The import of `Control.Monad' is redundant except perhaps to import instances from `Control.Monad' To import instances alone, use: import Control.Monad() GHC7.hs:10:0: Warning: The import of `Prelude' is redundant except perhaps to import instances from `Prelude' To import instances alone, use: import Prelude() Which is to be expected because the Prelude is imported implicitly. I get the same warnings in ghc-HEAD with and without NoImplicitPrelude: $ ~/ghc-HEAD/bin/ghc-7.1.20101029 --make GHC7.hs -Wall -fforce-recomp [1 of 1] Compiling Main ( GHC7.hs, GHC7.o ) GHC7.hs:9:1: Warning: The import of `Control.Monad' is redundant except perhaps to import instances from `Control.Monad' To import instances alone, use: import Control.Monad() GHC7.hs:10:1: Warning: The import of `Prelude' is redundant except perhaps to import instances from `Prelude' To import instances alone, use: import Prelude() Thanks, Bas