diff options
| -rw-r--r-- | Utility/BadPrelude.hs | 13 | ||||
| -rw-r--r-- | Utility/Misc.hs | 6 |
2 files changed, 12 insertions, 7 deletions
diff --git a/Utility/BadPrelude.hs b/Utility/BadPrelude.hs index 47d38ae7b..825adfa02 100644 --- a/Utility/BadPrelude.hs +++ b/Utility/BadPrelude.hs @@ -7,7 +7,8 @@ module Utility.BadPrelude where -{- read should be avoided, as it throws an error -} +{- read should be avoided, as it throws an error + - Instead, use: readMaybe -} read :: Read a => String -> a read = Prelude.read @@ -31,6 +32,16 @@ init = Prelude.init last :: [a] -> a last = Prelude.last +{- Attempts to read a value from a String. + - + - Ignores leading/trailing whitespace, and throws away any trailing + - text after the part that can be read. + -} +readMaybe :: (Read a) => String -> Maybe a +readMaybe s = case reads s of + ((x,_):_) -> Just x + _ -> Nothing + {- Like head but Nothing on empty list. -} headMaybe :: [a] -> Maybe a headMaybe [] = Nothing diff --git a/Utility/Misc.hs b/Utility/Misc.hs index e95ac4319..1d3c0e676 100644 --- a/Utility/Misc.hs +++ b/Utility/Misc.hs @@ -21,12 +21,6 @@ hGetContentsStrict = hGetContents >=> \s -> length s `seq` return s readFileStrict :: FilePath -> IO String readFileStrict = readFile >=> \s -> length s `seq` return s -{- Attempts to read a value from a String. -} -readMaybe :: (Read a) => String -> Maybe a -readMaybe s = case reads s of - ((x,_):_) -> Just x - _ -> Nothing - {- Like break, but the character matching the condition is not included - in the second result list. - |