module Test.Hspec.Compat (
showType
, showFullType
, readMaybe
, lookupEnv
, module Data.IORef
#if !MIN_VERSION_base(4,6,0)
, modifyIORef'
#endif
) where
#if !MIN_VERSION_base(4,3,0)
import Control.Monad.Trans.Error ()
#endif
import Data.Typeable (Typeable, typeOf, typeRepTyCon)
import Text.Read
import Data.IORef
import System.Environment
#if MIN_VERSION_base(4,4,0)
import Data.Typeable.Internal (tyConModule, tyConName)
#endif
#if !MIN_VERSION_base(4,6,0)
import qualified Text.ParserCombinators.ReadP as P
#endif
#if !MIN_VERSION_base(4,6,0)
modifyIORef' :: IORef a -> (a -> a) -> IO ()
modifyIORef' ref f = do
x <- readIORef ref
let x' = f x
x' `seq` writeIORef ref x'
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
lookupEnv :: String -> IO (Maybe String)
lookupEnv k = lookup k `fmap` getEnvironment
#endif
showType :: Typeable a => a -> String
showType a = let t = typeRepTyCon (typeOf a) in
#if MIN_VERSION_base(4,4,0)
show t
#else
(reverse . takeWhile (/= '.') . reverse . show) t
#endif
showFullType :: Typeable a => a -> String
showFullType a = let t = typeRepTyCon (typeOf a) in
#if MIN_VERSION_base(4,4,0)
tyConModule t ++ "." ++ tyConName t
#else
show t
#endif