From eed29a62d982f028370d4a9957bead22fcb27dda Mon Sep 17 00:00:00 2001 From: daniel Date: Tue, 5 Jun 2007 00:55:34 +0200 Subject: Contrib package for 6.4 users darcs-hash:20070604225534-c98ca-f7374f75c0e30ff72391ad1f226c94ca7519f590.gz --- BackCompat.hs | 41 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 41 insertions(+) create mode 100644 BackCompat.hs (limited to 'BackCompat.hs') diff --git a/BackCompat.hs b/BackCompat.hs new file mode 100644 index 0000000..b743b83 --- /dev/null +++ b/BackCompat.hs @@ -0,0 +1,41 @@ +module XMonadContrib.BackCompat (forM, forM_) where + +{- This file will contain all the things GHC 6.4 users need to compile xmonad. + - Currently, the steps to get compilation are: + - add the following line to StackSet.hs, Operations.hs, and Main.hs: + - import XMonadContrib.BackCompat + -} + +import Data.Map (Map, fromList) +import GHC.Read + +forM_ :: (Monad m) => [a] -> (a -> m b) -> m () +forM_ = flip mapM_ + +-- not used yet, but just in case +forM :: (Monad m) => [a] -> (a -> m b) -> m [b] +forM = flip mapM + +instance (Ord k, Read k, Read e) => Read (Map k e) where + readsPrec _ = \s1 -> do + ("{", s2) <- lex s1 + (xs, s3) <- readPairs s2 + ("}", s4) <- lex s3 + return (fromList xs, s4) + +-- parses a pair of things with the syntax a:=b +-- stolen from the GHC 6.6 sources +readPair :: (Read a, Read b) => ReadS (a,b) +readPair s = do (a, ct1) <- reads s + (":=", ct2) <- lex ct1 + (b, ct3) <- reads ct2 + return ((a,b), ct3) + +readPairs :: (Read a, Read b) => ReadS [(a,b)] +readPairs s1 = case readPair s1 of + [(p, s2)] -> case s2 of + (',':s3) -> do + (ps, s4) <- readPairs s3 + return (p:ps, s4) + _ -> [([p], s2)] + _ -> [([],s1)] -- cgit v1.2.3