using dropWhileEnd (#193).

This commit is contained in:
Kazu Yamamoto 2014-03-26 15:38:02 +09:00
parent 8238c632a8
commit 6e4d073c7d

View File

@ -112,7 +112,10 @@ getPackageDbDir sconf = do
return path
where
parse = head . filter ("package-db:" `isPrefixOf`) . lines
extractValue = fst . break isSpace . dropWhile isSpace . drop pkgDbKeyLen
extractValue = dropWhileEnd isSpace . dropWhile isSpace . drop pkgDbKeyLen
-- dropWhileEnd is not provided prior to base 4.5.0.0.
dropWhileEnd :: (a -> Bool) -> [a] -> [a]
dropWhileEnd p = foldr (\x xs -> if p x && null xs then [] else x : xs) []
-- | Adding necessary GHC options to the package db.
-- Exception is thrown if the string argument is incorrect.