+% ------------------------------------------------------------------------------
+% $Id: Prelude.lhs,v 1.26 2001/05/18 16:54:05 simonmar Exp $
+%
+% (c) The University of Glasgow, 1992-2000
+%
+
+\section[Prelude]{Module @Prelude@}
+
We add the option -fno-implicit-prelude here to tell the reader that
special names such as () and -> shouldn't be resolved to Prelude.()
and Prelude.-> (as they are normally). -- SDM 8/10/97
showChar, showString, readParen, showParen,
-- Everything corresponding to the Report's PreludeIO
- FilePath, IOError,
ioError, userError, catch,
- putChar, putStr, putStrLn, print,
- getChar, getLine, getContents, interact,
+ FilePath, IOError,
+ putChar,
+ putStr, putStrLn, print,
+ getChar,
+ getLine, getContents, interact,
readFile, writeFile, appendFile, readIO, readLn,
Bool(..),
Ord(..),
Enum(..),
Bounded(..),
- Num((+), (-), (*), negate, abs, signum, fromInteger),
- -- The fromInt method is exposed only by GlaExts
+ Num(..),
Real(..),
- Integral(quot, rem, div, mod, quotRem, divMod, toInteger),
- -- The toInt method is exposed only by GlaExts
+ Integral(..),
Fractional(..),
Floating(..),
RealFrac(..),
) where
+import Monad
+
import PrelBase
import PrelList
#ifndef USE_REPORT_PRELUDE
import PrelMaybe
import PrelShow
import PrelConc
-import PrelErr ( error )
+import PrelErr ( error, undefined )
-infixr 1 =<<
infixr 0 $!
\end{code}
\begin{code}
($!) :: (a -> b) -> a -> b
f $! x = x `seq` f x
-
--- It is expected that compilers will recognize this and insert error
--- messages which are more appropriate to the context in which undefined
--- appears.
-
-undefined :: a
-undefined = error "Prelude.undefined"
\end{code}
#endif
\end{code}
-
-%*********************************************************
-%* *
-\subsection{Prelude monad functions}
-%* *
-%*********************************************************
-
-\begin{code}
-{-# SPECIALISE (=<<) :: (a -> [b]) -> [a] -> [b] #-}
-(=<<) :: Monad m => (a -> m b) -> m a -> m b
-f =<< x = x >>= f
-
-sequence :: Monad m => [m a] -> m [a]
-{-# INLINE sequence #-}
-sequence ms = foldr k (return []) ms
- where
- k m m' = do { x <- m; xs <- m'; return (x:xs) }
-
-sequence_ :: Monad m => [m a] -> m ()
-{-# INLINE sequence_ #-}
-sequence_ ms = foldr (>>) (return ()) ms
-
-mapM :: Monad m => (a -> m b) -> [a] -> m [b]
-{-# INLINE mapM #-}
-mapM f as = sequence (map f as)
-
-mapM_ :: Monad m => (a -> m b) -> [a] -> m ()
-{-# INLINE mapM_ #-}
-mapM_ f as = sequence_ (map f as)
-\end{code}
-
-
-%*********************************************************
-%* *
-\subsection{Coercions}
-%* *
-%*********************************************************
-
-\begin{code}
-{-# SPECIALIZE fromIntegral ::
- Int -> Rational,
- Integer -> Rational,
- Int -> Int,
- Int -> Integer,
- Int -> Float,
- Int -> Double,
- Integer -> Int,
- Integer -> Integer,
- Integer -> Float,
- Integer -> Double #-}
-fromIntegral :: (Integral a, Num b) => a -> b
-fromIntegral = fromInteger . toInteger
-
-{-# SPECIALIZE realToFrac ::
- Double -> Rational,
- Rational -> Double,
- Float -> Rational,
- Rational -> Float
- #-}
-realToFrac :: (Real a, Fractional b) => a -> b
-realToFrac = fromRational . toRational
-
-{-# RULES
-"realToFrac/Double->Float" realToFrac = doubleToFloat
-"realToFrac/Float->Double" realToFrac = floatToDouble
-"realToFrac/Double->Double" realToFrac = id :: Double -> Double
-"realToFrac/Float->Float" realToFrac = id :: Float -> Float
-"realToFrac/Rational->Rational" realToFrac = id :: Rational -> Rational
- #-}
-
-doubleToFloat :: Double -> Float
-doubleToFloat (D# d) = F# (double2Float# d)
-
-floatToDouble :: Float -> Double
-floatToDouble (F# f) = D# (float2Double# f)
-
-\end{code}
-