module Text.Read (
module Base
, readEither
, readMaybe
) where
import "base" Text.Read as Base
#if !MIN_VERSION_base(4,6,0)
import qualified Text.ParserCombinators.ReadP as P
import Prelude
readEither :: Read a => String -> Either String a
readEither s =
case [ x | (x,"") <- readPrec_to_S read' minPrec s ] of
[x] -> Right x
[] -> Left "Prelude.read: no parse"
_ -> Left "Prelude.read: ambiguous parse"
where
read' =
do x <- readPrec
lift P.skipSpaces
return x
readMaybe :: Read a => String -> Maybe a
readMaybe s = case readEither s of
Left _ -> Nothing
Right a -> Just a
#endif