+% -----------------------------------------------------------------------------
+% $Id: PrelBase.lhs,v 1.36 2000/08/29 17:42:17 qrczak Exp $
%
-% (c) The GRASP/AQUA Project, Glasgow University, 1992-1996
+% (c) The University of Glasgow, 1992-2000
%
\section[PrelBase]{Module @PrelBase@}
-\begin{code}
-{-# OPTIONS -fno-implicit-prelude #-}
+The overall structure of the GHC Prelude is a bit tricky.
-module PrelBase(
- module PrelBase,
- module PrelGHC -- Re-export PrelGHC, to avoid lots of people
- -- having to import it explicitly
- ) where
+ a) We want to avoid "orphan modules", i.e. ones with instance
+ decls that don't belong either to a tycon or a class
+ defined in the same module
-import {-# SOURCE #-} PrelErr ( error )
-import PrelGHC
+ b) We want to avoid giant modules
-infixr 9 .
-infixl 9 !!
-infixl 7 *
-infixl 6 +, -
-infixr 5 ++, :
-infix 4 ==, /=, <, <=, >=, >
-infixr 3 &&
-infixr 2 ||
-infixl 1 >>, >>=
-infixr 0 $
-\end{code}
+So the rough structure is as follows, in (linearised) dependency order
-\begin{code}
-{-
-class Eval a
-data Bool = False | True
-data Int = I# Int#
-data Double = D# Double#
-data () = () --easier to do explicitly: deriving (Eq, Ord, Enum, Show, Bounded)
- -- (avoids weird-named functions, e.g., con2tag_()#
+PrelGHC Has no implementation. It defines built-in things, and
+ by importing it you bring them into scope.
+ The source file is PrelGHC.hi-boot, which is just
+ copied to make PrelGHC.hi
-data Maybe a = Nothing | Just a
-data Ordering = LT | EQ | GT deriving( Eq )
+ Classes: CCallable, CReturnable
-type String = [Char]
+PrelBase Classes: Eq, Ord, Functor, Monad
+ Types: list, (), Int, Bool, Ordering, Char, String
-data Char = C# Char#
-data [] a = [] | a : [a] -- do explicitly: deriving (Eq, Ord)
- -- to avoid weird names like con2tag_[]#
+PrelTup Types: tuples, plus instances for PrelBase classes
+PrelShow Class: Show, plus instances for PrelBase/PrelTup types
--------------- Stage 2 -----------------------
-not True = False
-not False = True
-True && x = x
-False && x = False
-otherwise = True
+PrelEnum Class: Enum, plus instances for PrelBase/PrelTup types
-maybe :: b -> (a -> b) -> Maybe a -> b
-maybe n f Nothing = n
-maybe n f (Just x) = f x
+PrelMaybe Type: Maybe, plus instances for PrelBase classes
--------------- Stage 3 -----------------------
-class Eq a where
- (==), (/=) :: a -> a -> Bool
+PrelNum Class: Num, plus instances for Int
+ Type: Integer, plus instances for all classes so far (Eq, Ord, Num, Show)
- x /= y = not (x == y)
+ Integer is needed here because it is mentioned in the signature
+ of 'fromInteger' in class Num
--- f :: Eq a => a -> a -> Bool
-f x y = x == y
+PrelReal Classes: Real, Integral, Fractional, RealFrac
+ plus instances for Int, Integer
+ Types: Ratio, Rational
+ plus intances for classes so far
-g :: Eq a => a -> a -> Bool
-g x y = f x y
+ Rational is needed here because it is mentioned in the signature
+ of 'toRational' in class Real
--------------- Stage 4 -----------------------
+Ix Classes: Ix, plus instances for Int, Bool, Char, Integer, Ordering, tuples
-class (Eq a) => Ord a where
- compare :: a -> a -> Ordering
- (<), (<=), (>=), (>):: a -> a -> Bool
- max, min :: a -> a -> a
+PrelArr Types: Array, MutableArray, MutableVar
--- An instance of Ord should define either compare or <=
--- Using compare can be more efficient for complex types.
- compare x y
- | x == y = EQ
- | x <= y = LT
- | otherwise = GT
+ Does *not* contain any ByteArray stuff (see PrelByteArr)
+ Arrays are used by a function in PrelFloat
- x <= y = compare x y /= GT
- x < y = compare x y == LT
- x >= y = compare x y /= LT
- x > y = compare x y == GT
- max x y = case (compare x y) of { LT -> y ; EQ -> x ; GT -> x }
- min x y = case (compare x y) of { LT -> x ; EQ -> x ; GT -> y }
+PrelFloat Classes: Floating, RealFloat
+ Types: Float, Double, plus instances of all classes so far
-eqInt (I# x) (I# y) = x ==# y
+ This module contains everything to do with floating point.
+ It is a big module (900 lines)
+ With a bit of luck, many modules can be compiled without ever reading PrelFloat.hi
-instance Eq Int where
- (==) x y = x `eqInt` y
+PrelByteArr Types: ByteArray, MutableByteArray
+
+ We want this one to be after PrelFloat, because it defines arrays
+ of unboxed floats.
-instance Ord Int where
- compare x y = error "help"
-
-class Bounded a where
- minBound, maxBound :: a
+Other Prelude modules are much easier with fewer complex dependencies.
-type ShowS = String -> String
-class Show a where
- showsPrec :: Bool -> a -> ShowS
- showList :: [a] -> ShowS
+\begin{code}
+{-# OPTIONS -fno-implicit-prelude #-}
- showList ls = showList__ (showsPrec True) ls
+module PrelBase
+ (
+ module PrelBase,
+ module PrelGHC, -- Re-export PrelGHC, PrelErr & PrelNum, to avoid lots
+ module PrelErr, -- of people having to import it explicitly
+ module PrelNum
+ )
+ where
-showList__ :: (a -> ShowS) -> [a] -> ShowS
-showList__ showx [] = showString "[]"
+import PrelGHC
+import {-# SOURCE #-} PrelErr
+import {-# SOURCE #-} PrelNum
-showString :: String -> ShowS
-showString = (++)
+infixr 9 .
+infixr 5 ++, :
+infix 4 ==, /=, <, <=, >=, >
+infixr 3 &&
+infixr 2 ||
+infixl 1 >>, >>=
+infixr 0 $
-[] ++ [] = []
+default () -- Double isn't available yet
+\end{code}
-shows :: (Show a) => a -> ShowS
-shows = showsPrec True
--- show :: (Show a) => a -> String
---show x = shows x ""
+%*********************************************************
+%* *
+\subsection{DEBUGGING STUFF}
+%* (for use when compiling PrelBase itself doesn't work)
+%* *
+%*********************************************************
+
+\begin{code}
+{-
+data Bool = False | True
+data Ordering = LT | EQ | GT
+data Char = C# Char#
+type String = [Char]
+data Int = I# Int#
+data () = ()
+-- data [] a = MkNil
+
+not True = False
+(&&) True True = True
+otherwise = True
+
+build = error "urk"
+foldr = error "urk"
+
+unpackCString# :: Addr# -> [Char]
+unpackFoldrCString# :: Addr# -> (Char -> a -> a) -> a -> a
+unpackAppendCString# :: Addr# -> [Char] -> [Char]
+unpackCStringUtf8# :: Addr# -> [Char]
+unpackCString# a = error "urk"
+unpackFoldrCString# a = error "urk"
+unpackAppendCString# a = error "urk"
+unpackCStringUtf8# a = error "urk"
-}
\end{code}
%*********************************************************
%* *
-\subsection{Standard classes @Eq@, @Ord@, @Bounded@, @Eval@}
+\subsection{Standard classes @Eq@, @Ord@}
%* *
%*********************************************************
class Eq a where
(==), (/=) :: a -> a -> Bool
- x /= y = not (x == y)
+-- x /= y = not (x == y)
+-- x == y = not (x /= y)
+-- x /= y = True
+ (/=) x y = not ((==) x y)
+ x == y = True
class (Eq a) => Ord a where
compare :: a -> a -> Ordering
-- Using compare can be more efficient for complex types.
compare x y
| x == y = EQ
- | x <= y = LT
+ | x <= y = LT -- NB: must be '<=' not '<' to validate the
+ -- above claim about the minimal things that can
+ -- be defined for an instance of Ord
| otherwise = GT
- x <= y = compare x y /= GT
- x < y = compare x y == LT
- x >= y = compare x y /= LT
- x > y = compare x y == GT
- max x y = case (compare x y) of { LT -> y ; EQ -> x ; GT -> x }
- min x y = case (compare x y) of { LT -> x ; EQ -> x ; GT -> y }
-
-class Bounded a where
- minBound, maxBound :: a
+ x <= y = case compare x y of { GT -> False; _other -> True }
+ x < y = case compare x y of { LT -> True; _other -> False }
+ x >= y = case compare x y of { LT -> False; _other -> True }
+ x > y = case compare x y of { GT -> True; _other -> False }
-class Eval a
+ -- These two default methods use '>' rather than compare
+ -- because the latter is often more expensive
+ max x y = if x > y then x else y
+ min x y = if x > y then y else x
\end{code}
%*********************************************************
%* *
-\subsection{Monadic classes @Functor@, @Monad@, @MonadZero@, @MonadPlus@}
+\subsection{Monadic classes @Functor@, @Monad@ }
%* *
%*********************************************************
\begin{code}
class Functor f where
- map :: (a -> b) -> f a -> f b
+ fmap :: (a -> b) -> f a -> f b
class Monad m where
(>>=) :: m a -> (a -> m b) -> m b
(>>) :: m a -> m b -> m b
return :: a -> m a
+ fail :: String -> m a
m >> k = m >>= \_ -> k
+ fail s = error s
-class (Monad m) => MonadZero m where
- zero :: m a
-
-class (MonadZero m) => MonadPlus m where
- (++) :: m a -> m a -> m a
\end{code}
%*********************************************************
%* *
-\subsection{Classes @Num@ and @Enum@}
-%* *
-%*********************************************************
-
-\begin{code}
-class Enum a where
- toEnum :: Int -> a
- fromEnum :: a -> Int
- enumFrom :: a -> [a] -- [n..]
- enumFromThen :: a -> a -> [a] -- [n,n'..]
- enumFromTo :: a -> a -> [a] -- [n..m]
- enumFromThenTo :: a -> a -> a -> [a] -- [n,n'..m]
-
- enumFromTo n m = map toEnum [fromEnum n .. fromEnum m]
- enumFromThenTo n n' m
- = map toEnum [fromEnum n, fromEnum n' .. fromEnum m]
-
-class (Eq a, Show a, Eval a) => Num a where
- (+), (-), (*) :: a -> a -> a
- negate :: a -> a
- abs, signum :: a -> a
- fromInteger :: Integer -> a
- fromInt :: Int -> a -- partain: Glasgow extension
-
- x - y = x + negate y
- fromInt (I# i#) = fromInteger (int2Integer# i#)
- -- Go via the standard class-op if the
- -- non-standard one ain't provided
-\end{code}
-
-\begin{code}
-succ, pred :: Enum a => a -> a
-succ = toEnum . (+1) . fromEnum
-pred = toEnum . (subtract 1) . fromEnum
-
-chr = (toEnum :: Int -> Char)
-ord = (fromEnum :: Char -> Int)
-
-ord_0 :: Num a => a
-ord_0 = fromInt (ord '0')
-
-{-# GENERATE_SPECS subtract a{Int#,Double#,Int,Double,Complex(Double#),Complex(Double)} #-}
-subtract :: (Num a) => a -> a -> a
-subtract x y = y - x
-\end{code}
-
-
-%*********************************************************
-%* *
-\subsection{The @Show@ class}
-%* *
-%*********************************************************
-
-\begin{code}
-type ShowS = String -> String
-
-class Show a where
- showsPrec :: Int -> a -> ShowS
- showList :: [a] -> ShowS
-
- showList ls = showList__ (showsPrec 0) ls
-\end{code}
-
-%*********************************************************
-%* *
\subsection{The list type}
%* *
%*********************************************************
data [] a = [] | a : [a] -- do explicitly: deriving (Eq, Ord)
-- to avoid weird names like con2tag_[]#
+
instance (Eq a) => Eq [a] where
+{-
+ {-# SPECIALISE instance Eq [Char] #-}
+-}
[] == [] = True
(x:xs) == (y:ys) = x == y && xs == ys
- xs == ys = False
+ _xs == _ys = False
+
xs /= ys = if (xs == ys) then False else True
instance (Ord a) => Ord [a] where
+{-
+ {-# SPECIALISE instance Ord [Char] #-}
+-}
a < b = case compare a b of { LT -> True; EQ -> False; GT -> False }
a <= b = case compare a b of { LT -> True; EQ -> True; GT -> False }
a >= b = case compare a b of { LT -> False; EQ -> True; GT -> True }
a > b = case compare a b of { LT -> False; EQ -> False; GT -> True }
- max a b = case compare a b of { LT -> b; EQ -> a; GT -> a }
- min a b = case compare a b of { LT -> a; EQ -> a; GT -> b }
-
compare [] [] = EQ
- compare (x:xs) [] = GT
- compare [] (y:ys) = LT
+ compare (_:_) [] = GT
+ compare [] (_:_) = LT
compare (x:xs) (y:ys) = case compare x y of
LT -> LT
GT -> GT
EQ -> compare xs ys
instance Functor [] where
- map f [] = []
- map f (x:xs) = f x : map f xs
+ fmap = map
instance Monad [] where
m >>= k = foldr ((++) . k) [] m
m >> k = foldr ((++) . (\ _ -> k)) [] m
return x = [x]
-
-instance MonadZero [] where
- zero = []
-
-instance MonadPlus [] where
-#ifdef USE_REPORT_PRELUDE
- xs ++ ys = foldr (:) ys xs
-#else
- [] ++ ys = ys
- (x:xs) ++ ys = x : (xs ++ ys)
-#endif
-
-instance (Show a) => Show [a] where
- showsPrec p = showList
- showList ls = showList__ (showsPrec 0) ls
-\end{code}
-
+ fail _ = []
\end{code}
A few list functions that appear here because they are used here.
The rest of the prelude list functions are in PrelList.
+----------------------------------------------
+-- foldr/build/augment
+----------------------------------------------
+
\begin{code}
-foldr :: (a -> b -> b) -> b -> [a] -> b
-foldr f z [] = z
-foldr f z (x:xs) = f x (foldr f z xs)
-
--- takeWhile, applied to a predicate p and a list xs, returns the longest
--- prefix (possibly empty) of xs of elements that satisfy p. dropWhile p xs
--- returns the remaining suffix. Span p xs is equivalent to
--- (takeWhile p xs, dropWhile p xs), while break p uses the negation of p.
-
-takeWhile :: (a -> Bool) -> [a] -> [a]
-takeWhile p [] = []
-takeWhile p (x:xs)
- | p x = x : takeWhile p xs
- | otherwise = []
-
-dropWhile :: (a -> Bool) -> [a] -> [a]
-dropWhile p [] = []
-dropWhile p xs@(x:xs')
- | p x = dropWhile p xs'
- | otherwise = xs
-
--- List index (subscript) operator, 0-origin
-(!!) :: [a] -> Int -> a
-#ifdef USE_REPORT_PRELUDE
-(x:_) !! 0 = x
-(_:xs) !! n | n > 0 = xs !! (n-1)
-(_:_) !! _ = error "PreludeList.!!: negative index"
-[] !! _ = error "PreludeList.!!: index too large"
-#else
--- HBC version (stolen), then unboxified
--- The semantics is not quite the same for error conditions
--- in the more efficient version.
---
-_ !! n | n < 0 = error "(!!){PreludeList}: negative index\n"
-xs !! n = sub xs (case n of { I# n# -> n# })
- where sub :: [a] -> Int# -> a
- sub [] _ = error "(!!){PreludeList}: index too large\n"
- sub (x:xs) n# = if n# ==# 0#
- then x
- else sub xs (n# -# 1#)
-#endif
+foldr :: (a -> b -> b) -> b -> [a] -> b
+-- foldr _ z [] = z
+-- foldr f z (x:xs) = f x (foldr f z xs)
+{-# INLINE foldr #-}
+foldr k z xs = go xs
+ where
+ go [] = z
+ go (x:xs) = x `k` go xs
+
+build :: forall a. (forall b. (a -> b -> b) -> b -> b) -> [a]
+{-# INLINE 2 build #-}
+ -- The INLINE is important, even though build is tiny,
+ -- because it prevents [] getting inlined in the version that
+ -- appears in the interface file. If [] *is* inlined, it
+ -- won't match with [] appearing in rules in an importing module.
+ --
+ -- The "2" says to inline in phase 2
+
+build g = g (:) []
+
+augment :: forall a. (forall b. (a->b->b) -> b -> b) -> [a] -> [a]
+{-# INLINE 2 augment #-}
+augment g xs = g (:) xs
+
+{-# RULES
+"fold/build" forall k z (g::forall b. (a->b->b) -> b -> b) .
+ foldr k z (build g) = g k z
+
+"foldr/augment" forall k z xs (g::forall b. (a->b->b) -> b -> b) .
+ foldr k z (augment g xs) = g k (foldr k z xs)
+
+"foldr/id" foldr (:) [] = \x->x
+"foldr/app" forall xs ys. foldr (:) ys xs = append xs ys
+
+"foldr/cons" forall k z x xs. foldr k z (x:xs) = k x (foldr k z xs)
+"foldr/nil" forall k z. foldr k z [] = z
+
+"augment/build" forall (g::forall b. (a->b->b) -> b -> b)
+ (h::forall b. (a->b->b) -> b -> b) .
+ augment g (build h) = build (\c n -> g c (h c n))
+"augment/nil" forall (g::forall b. (a->b->b) -> b -> b) .
+ augment g [] = build g
+ #-}
+
+-- This rule is true, but not (I think) useful:
+-- augment g (augment h t) = augment (\cn -> g c (h c n)) t
\end{code}
-%*********************************************************
-%* *
-\subsection{Type @Void@}
-%* *
-%*********************************************************
+----------------------------------------------
+-- map
+----------------------------------------------
+
+\begin{code}
+map :: (a -> b) -> [a] -> [b]
+map = mapList
-The type @Void@ is built in, but it needs a @Show@ instance.
+-- Note eta expanded
+mapFB c f x ys = c (f x) ys
+
+mapList :: (a -> b) -> [a] -> [b]
+mapList _ [] = []
+mapList f (x:xs) = f x : mapList f xs
+
+{-# RULES
+"map" forall f xs. map f xs = build (\c n -> foldr (mapFB c f) n xs)
+"mapFB" forall c f g. mapFB (mapFB c f) g = mapFB c (f.g)
+"mapList" forall f. foldr (mapFB (:) f) [] = mapList f
+ #-}
+\end{code}
+
+----------------------------------------------
+-- append
+----------------------------------------------
\begin{code}
-void :: Void
-void = error "You tried to evaluate void"
+(++) :: [a] -> [a] -> [a]
+(++) = append
+
+{-# RULES
+ "++" forall xs ys. (++) xs ys = augment (\c n -> foldr c n xs) ys
+ #-}
-instance Show Void where
- showsPrec p f = showString "<<void>>"
- showList ls = showList__ (showsPrec 0) ls
+append :: [a] -> [a] -> [a]
+append [] ys = ys
+append (x:xs) ys = x : append xs ys
\end{code}
%*********************************************************
\begin{code}
-data Bool = False | True deriving (Eq, Ord, Enum, Bounded, Show {- Read -})
+data Bool = False | True deriving (Eq, Ord)
+ -- Read in PrelRead, Show in PrelShow
-- Boolean functions
(&&), (||) :: Bool -> Bool -> Bool
True && x = x
-False && x = False
-True || x = True
+False && _ = False
+True || _ = True
False || x = x
not :: Bool -> Bool
the renamer currently *always* asks for () to be in scope, so that
ccalls can use () as their default type; so when compiling PrelBase we
need (). (We could arrange suck in () only if -fglasgow-exts, but putting
-it here seems more direct.
+it here seems more direct.)
\begin{code}
-data () = () --easier to do explicitly: deriving (Eq, Ord, Enum, Show, Bounded)
- -- (avoids weird-named functions, e.g., con2tag_()#
+data () = ()
instance Eq () where
() == () = True
max () () = ()
min () () = ()
compare () () = EQ
-
-instance Enum () where
- toEnum 0 = ()
- toEnum _ = error "Prelude.Enum.().toEnum: argument not 0"
- fromEnum () = 0
- enumFrom () = [()]
- enumFromThen () () = [()]
- enumFromTo () () = [()]
- enumFromThenTo () () () = [()]
-
-instance Show () where
- showsPrec p () = showString "()"
- showList ls = showList__ (showsPrec 0) ls
\end{code}
+
%*********************************************************
%* *
\subsection{Type @Ordering@}
%*********************************************************
\begin{code}
-data Ordering = LT | EQ | GT deriving (Eq, Ord, Enum, Bounded, Show {- Read -})
+data Ordering = LT | EQ | GT deriving (Eq, Ord)
+ -- Read in PrelRead, Show in PrelShow
\end{code}
\begin{code}
type String = [Char]
-data Char = C# Char# deriving (Eq, Ord)
-
-instance Enum Char where
- toEnum (I# i) | i >=# 0# && i <=# 255# = C# (chr# i)
- | otherwise = error ("Prelude.Enum.Char.toEnum:out of range: " ++ show (I# i))
- fromEnum (C# c) = I# (ord# c)
+data Char = C# Char#
- enumFrom (C# c) = efttCh (ord# c) 1# (># 255#)
- enumFromTo (C# c1) (C# c2) = efttCh (ord# c1) 1# (># (ord# c2))
+-- We don't use deriving for Eq and Ord, because for Ord the derived
+-- instance defines only compare, which takes two primops. Then
+-- '>' uses compare, and therefore takes two primops instead of one.
- enumFromThen (C# c1) (C# c2)
- | c1 `leChar#` c2 = efttCh (ord# c1) (ord# c2 -# ord# c1) (># 255#)
- | otherwise = efttCh (ord# c1) (ord# c2 -# ord# c1) (<# 0#)
+instance Eq Char where
+ (C# c1) == (C# c2) = c1 `eqChar#` c2
+ (C# c1) /= (C# c2) = c1 `neChar#` c2
- enumFromThenTo (C# c1) (C# c2) (C# c3)
- | c1 `leChar#` c2 = efttCh (ord# c1) (ord# c2 -# ord# c1) (># (ord# c3))
- | otherwise = efttCh (ord# c1) (ord# c2 -# ord# c1) (<# (ord# c3))
+instance Ord Char where
+ (C# c1) > (C# c2) = c1 `gtChar#` c2
+ (C# c1) >= (C# c2) = c1 `geChar#` c2
+ (C# c1) <= (C# c2) = c1 `leChar#` c2
+ (C# c1) < (C# c2) = c1 `ltChar#` c2
-efttCh :: Int# -> Int# -> (Int# -> Bool) -> [Char]
-efttCh now step done
- = go now
- where
- go now | done now = []
- | otherwise = C# (chr# now) : go (now +# step)
+chr :: Int -> Char
+chr (I# i) | i >=# 0#
+#if INT_SIZE_IN_BYTES > 4
+ && i <=# 0x7FFFFFFF#
+#endif
+ = C# (chr# i)
+ | otherwise = error ("Prelude.chr: bad argument")
-instance Show Char where
- showsPrec p '\'' = showString "'\\''"
- showsPrec p c = showChar '\'' . showLitChar c . showChar '\''
+unsafeChr :: Int -> Char
+unsafeChr (I# i) = C# (chr# i)
- showList cs = showChar '"' . showl cs
- where showl "" = showChar '"'
- showl ('"':cs) = showString "\\\"" . showl cs
- showl (c:cs) = showLitChar c . showl cs
+ord :: Char -> Int
+ord (C# c) = I# (ord# c)
\end{code}
-\begin{code}
-isAscii, isLatin1, isControl, isPrint, isSpace, isUpper,
- isLower, isAlpha, isDigit, isOctDigit, isHexDigit, isAlphanum :: Char -> Bool
-isAscii c = fromEnum c < 128
-isLatin1 c = c <= '\xff'
-isControl c = c < ' ' || c >= '\DEL' && c <= '\x9f'
-isPrint c = not (isControl c)
-
--- isSpace includes non-breaking space
--- Done with explicit equalities both for efficiency, and to avoid a tiresome
--- recursion with PrelList elem
-isSpace c = c == ' ' ||
- c == '\t' ||
- c == '\n' ||
- c == '\r' ||
- c == '\f' ||
- c == '\v' ||
- c == '\xa0'
-
--- The upper case ISO characters have the multiplication sign dumped
--- randomly in the middle of the range. Go figure.
-isUpper c = c >= 'A' && c <= 'Z' ||
- c >= '\xC0' && c <= '\xD6' ||
- c >= '\xD8' && c <= '\xDE'
--- The lower case ISO characters have the division sign dumped
--- randomly in the middle of the range. Go figure.
-isLower c = c >= 'a' && c <= 'z' ||
- c >= '\xDF' && c <= '\xF6' ||
- c >= '\xF8' && c <= '\xFF'
-isAlpha c = isLower c || isUpper c
-isDigit c = c >= '0' && c <= '9'
-isOctDigit c = c >= '0' && c <= '7'
-isHexDigit c = isDigit c || c >= 'A' && c <= 'F' ||
- c >= 'a' && c <= 'f'
-isAlphanum c = isAlpha c || isDigit c
-
--- Case-changing operations
-
-toUpper, toLower :: Char -> Char
-toUpper c | isLower c && c /= '\xDF' && c /= '\xFF'
- = toEnum (fromEnum c - fromEnum 'a' + fromEnum 'A')
- | otherwise = c
-
-toLower c | isUpper c = toEnum (fromEnum c - fromEnum 'A'
- + fromEnum 'a')
- | otherwise = c
-
-asciiTab = -- Using an array drags in the array module. listArray ('\NUL', ' ')
- ["NUL", "SOH", "STX", "ETX", "EOT", "ENQ", "ACK", "BEL",
- "BS", "HT", "LF", "VT", "FF", "CR", "SO", "SI",
- "DLE", "DC1", "DC2", "DC3", "DC4", "NAK", "SYN", "ETB",
- "CAN", "EM", "SUB", "ESC", "FS", "GS", "RS", "US",
- "SP"]
-\end{code}
-
%*********************************************************
%* *
\subsection{Type @Int@}
\begin{code}
data Int = I# Int#
+zeroInt, oneInt, twoInt, maxInt, minInt :: Int
+zeroInt = I# 0#
+oneInt = I# 1#
+twoInt = I# 2#
+minInt = I# (-2147483648#) -- GHC <= 2.09 had this at -2147483647
+maxInt = I# 2147483647#
+
instance Eq Int where
(==) x y = x `eqInt` y
(/=) x y = x `neInt` y
(<=) x y = leInt x y
(>=) x y = geInt x y
(>) x y = gtInt x y
- max x y = case (compareInt x y) of { LT -> y ; EQ -> x ; GT -> x }
- min x y = case (compareInt x y) of { LT -> x ; EQ -> x ; GT -> y }
+compareInt :: Int -> Int -> Ordering
(I# x) `compareInt` (I# y) | x <# y = LT
| x ==# y = EQ
| otherwise = GT
-
-instance Enum Int where
- toEnum x = x
- fromEnum x = x
-
-#ifndef USE_FOLDR_BUILD
- enumFrom (I# c) = eftInt c 1#
- enumFromTo (I# c1) (I# c2) = efttInt c1 1# (># c2)
- enumFromThen (I# c1) (I# c2) = eftInt c1 (c2 -# c1)
-
- enumFromThenTo (I# c1) (I# c2) (I# c3)
- | c1 <=# c2 = efttInt c1 (c2 -# c1) (># c3)
- | otherwise = efttInt c1 (c2 -# c1) (<# c3)
-
-#else
- {-# INLINE enumFrom #-}
- {-# INLINE enumFromTo #-}
- enumFrom x = build (\ c _ ->
- let g x = x `c` g (x `plusInt` 1) in g x)
- enumFromTo x y = build (\ c n ->
- let g x = if x <= y then x `c` g (x `plusInt` 1) else n in g x)
-#endif
-
-efttInt :: Int# -> Int# -> (Int# -> Bool) -> [Int]
-efttInt now step done
- = go now
- where
- go now | done now = []
- | otherwise = I# now : go (now +# step)
-
-eftInt :: Int# -> Int# -> [Int]
-eftInt now step
- = go now
- where
- go now = I# now : go (now +# step)
-
-
-instance Num Int where
- (+) x y = plusInt x y
- (-) x y = minusInt x y
- negate x = negateInt x
- (*) x y = timesInt x y
- abs n = if n `geInt` 0 then n else (negateInt n)
-
- signum n | n `ltInt` 0 = negateInt 1
- | n `eqInt` 0 = 0
- | otherwise = 1
-
- fromInteger (J# a# s# d#)
- = case (integer2Int# a# s# d#) of { i# -> I# i# }
-
- fromInt n = n
-
-instance Show Int where
- showsPrec p n = showSignedInt p n
- showList ls = showList__ (showsPrec 0) ls
-\end{code}
-
-
-%*********************************************************
-%* *
-\subsection{Type @Integer@, @Float@, @Double@}
-%* *
-%*********************************************************
-
-Just the type declarations. If we don't actually use any @Integers@ we'd
-rather not link the @Integer@ module at all; and the default-decl stuff
-in the renamer tends to slurp in @Double@ regardless.
-
-\begin{code}
-data Float = F# Float#
-data Double = D# Double#
-data Integer = J# Int# Int# ByteArray#
\end{code}
%*********************************************************
\begin{code}
-instance Eval (a -> b)
-
-instance Show (a -> b) where
- showsPrec p f = showString "<<function>>"
- showList ls = showList__ (showsPrec 0) ls
-
-
-- identity function
id :: a -> a
id x = x
-- function composition
{-# INLINE (.) #-}
-{-# GENERATE_SPECS (.) a b c #-}
(.) :: (b -> c) -> (a -> b) -> a -> c
(.) f g x = f (g x)
asTypeOf = const
\end{code}
-
%*********************************************************
%* *
-\subsection{Miscellaneous}
+\subsection{CCallable instances}
%* *
%*********************************************************
+Defined here to avoid orphans
\begin{code}
-data Lift a = Lift a
-{-# GENERATE_SPECS data a :: Lift a #-}
-\end{code}
-
-
-
-
-%*********************************************************
-%* *
-\subsection{Support code for @Show@}
-%* *
-%*********************************************************
-
-\begin{code}
-shows :: (Show a) => a -> ShowS
-shows = showsPrec 0
-
-show :: (Show a) => a -> String
-show x = shows x ""
-
-showChar :: Char -> ShowS
-showChar = (:)
+instance CCallable Char
+instance CReturnable Char
-showString :: String -> ShowS
-showString = (++)
-
-showParen :: Bool -> ShowS -> ShowS
-showParen b p = if b then showChar '(' . p . showChar ')' else p
-
-{-# GENERATE_SPECS showList__ a #-}
-showList__ :: (a -> ShowS) -> [a] -> ShowS
-
-showList__ showx [] = showString "[]"
-showList__ showx (x:xs) = showChar '[' . showx x . showl xs
- where
- showl [] = showChar ']'
- showl (x:xs) = showString ", " . showx x . showl xs
-
-showSpace :: ShowS
-showSpace = {-showChar ' '-} \ xs -> ' ' : xs
-\end{code}
-
-Code specific for characters
-
-\begin{code}
-showLitChar :: Char -> ShowS
-showLitChar c | c > '\DEL' = showChar '\\' . protectEsc isDigit (shows (ord c))
-showLitChar '\DEL' = showString "\\DEL"
-showLitChar '\\' = showString "\\\\"
-showLitChar c | c >= ' ' = showChar c
-showLitChar '\a' = showString "\\a"
-showLitChar '\b' = showString "\\b"
-showLitChar '\f' = showString "\\f"
-showLitChar '\n' = showString "\\n"
-showLitChar '\r' = showString "\\r"
-showLitChar '\t' = showString "\\t"
-showLitChar '\v' = showString "\\v"
-showLitChar '\SO' = protectEsc (== 'H') (showString "\\SO")
-showLitChar c = showString ('\\' : asciiTab!!ord c)
-
-protectEsc p f = f . cont
- where cont s@(c:_) | p c = "\\&" ++ s
- cont s = s
-
-intToDigit :: Int -> Char
-intToDigit i
- | i >= 0 && i <= 9 = toEnum (fromEnum '0' + i)
- | i >= 10 && i <= 15 = toEnum (fromEnum 'a' + i -10)
- | otherwise = error "Char.intToDigit: not a digit" ++ show i)
+instance CCallable Int
+instance CReturnable Int
+instance CReturnable () -- Why, exactly?
\end{code}
-Code specific for Ints.
-
-\begin{code}
-showSignedInt :: Int -> Int -> ShowS
-showSignedInt p (I# n) r
- = -- from HBC version; support code follows
- if n <# 0# && p > 6 then '(':itos n++(')':r) else itos n ++ r
-
-itos :: Int# -> String
-itos n =
- if n <# 0# then
- if negateInt# n <# 0# then
- -- n is minInt, a difficult number
- itos (n `quotInt#` 10#) ++ itos' (negateInt# (n `remInt#` 10#)) []
- else
- '-':itos' (negateInt# n) []
- else
- itos' n []
- where
- itos' :: Int# -> String -> String
- itos' n cs =
- if n <# 10# then
- C# (chr# (n +# ord# '0'#)) : cs
- else
- itos' (n `quotInt#` 10#) (C# (chr# (n `remInt#` 10# +# ord# '0'#)) : cs)
-\end{code}
%*********************************************************
%* *
\begin{code}
{-# INLINE eqInt #-}
{-# INLINE neInt #-}
-
+{-# INLINE gtInt #-}
+{-# INLINE geInt #-}
+{-# INLINE ltInt #-}
+{-# INLINE leInt #-}
+{-# INLINE plusInt #-}
+{-# INLINE minusInt #-}
+{-# INLINE timesInt #-}
+{-# INLINE quotInt #-}
+{-# INLINE remInt #-}
+{-# INLINE negateInt #-}
+
+plusInt, minusInt, timesInt, quotInt, remInt, gcdInt :: Int -> Int -> Int
plusInt (I# x) (I# y) = I# (x +# y)
minusInt(I# x) (I# y) = I# (x -# y)
timesInt(I# x) (I# y) = I# (x *# y)
quotInt (I# x) (I# y) = I# (quotInt# x y)
-remInt (I# x) (I# y) = I# (remInt# x y)
-negateInt (I# x) = I# (negateInt# x)
+remInt (I# x) (I# y) = I# (remInt# x y)
+
+gcdInt (I# a) (I# b) = g a b
+ where g 0# 0# = error "PrelBase.gcdInt: gcd 0 0 is undefined"
+ g 0# _ = I# absB
+ g _ 0# = I# absA
+ g _ _ = I# (gcdInt# absA absB)
+
+ absInt x = if x <# 0# then negateInt# x else x
+
+ absA = absInt a
+ absB = absInt b
+
+negateInt :: Int -> Int
+negateInt (I# x) = I# (negateInt# x)
+
+divInt, modInt :: Int -> Int -> Int
+x `divInt` y
+ | x > zeroInt && y < zeroInt = quotInt ((x `minusInt` y) `minusInt` oneInt) y
+ | x < zeroInt && y > zeroInt = quotInt ((x `minusInt` y) `plusInt` oneInt) y
+ | otherwise = quotInt x y
+
+x `modInt` y
+ | x > zeroInt && y < zeroInt ||
+ x < zeroInt && y > zeroInt = if r/=zeroInt then r `plusInt` y else zeroInt
+ | otherwise = r
+ where
+ r = remInt x y
+
+gtInt, geInt, eqInt, neInt, ltInt, leInt :: Int -> Int -> Bool
gtInt (I# x) (I# y) = x ># y
geInt (I# x) (I# y) = x >=# y
eqInt (I# x) (I# y) = x ==# y
ltInt (I# x) (I# y) = x <# y
leInt (I# x) (I# y) = x <=# y
\end{code}
+
+
+%********************************************************
+%* *
+\subsection{Unpacking C strings}
+%* *
+%********************************************************
+
+This code is needed for virtually all programs, since it's used for
+unpacking the strings of error messages.
+
+\begin{code}
+unpackCString# :: Addr# -> [Char]
+unpackCString# a = unpackCStringList# a
+
+unpackCStringList# :: Addr# -> [Char]
+unpackCStringList# addr
+ = unpack 0#
+ where
+ unpack nh
+ | ch `eqChar#` '\0'# = []
+ | otherwise = C# ch : unpack (nh +# 1#)
+ where
+ ch = indexCharOffAddr# addr nh
+
+unpackAppendCString# :: Addr# -> [Char] -> [Char]
+unpackAppendCString# addr rest
+ = unpack 0#
+ where
+ unpack nh
+ | ch `eqChar#` '\0'# = rest
+ | otherwise = C# ch : unpack (nh +# 1#)
+ where
+ ch = indexCharOffAddr# addr nh
+
+unpackFoldrCString# :: Addr# -> (Char -> a -> a) -> a -> a
+unpackFoldrCString# addr f z
+ = unpack 0#
+ where
+ unpack nh
+ | ch `eqChar#` '\0'# = z
+ | otherwise = C# ch `f` unpack (nh +# 1#)
+ where
+ ch = indexCharOffAddr# addr nh
+
+unpackCStringUtf8# :: Addr# -> [Char]
+unpackCStringUtf8# addr
+ = unpack 0#
+ where
+ unpack nh
+ | ch `eqChar#` '\0'# = []
+ | ch `leChar#` '\x7F'# = C# ch : unpack (nh +# 1#)
+ | ch `leChar#` '\xDF'# = C# (chr# ((ord# ch `iShiftL#` 6#) +#
+ (ord# (indexCharOffAddr# addr (nh +# 1#))) -# 0x3080#))
+ : unpack (nh +# 2#)
+ | ch `leChar#` '\xEF'# = C# (chr# ((ord# ch `iShiftL#` 12#) +#
+ (ord# (indexCharOffAddr# addr (nh +# 1#)) `iShiftL#` 6#) +#
+ (ord# (indexCharOffAddr# addr (nh +# 2#))) -# 0xE2080#))
+ : unpack (nh +# 3#)
+ | ch `leChar#` '\xF7'# = C# (chr# ((ord# ch `iShiftL#` 18#) +#
+ (ord# (indexCharOffAddr# addr (nh +# 1#)) `iShiftL#` 12#) +#
+ (ord# (indexCharOffAddr# addr (nh +# 2#)) `iShiftL#` 6#) +#
+ (ord# (indexCharOffAddr# addr (nh +# 3#))) -# 0x3C82080#))
+ : unpack (nh +# 4#)
+ | ch `leChar#` '\xFB'# = C# (chr# ((ord# ch -# 0xF8# `iShiftL#` 24#) +#
+ (ord# (indexCharOffAddr# addr (nh +# 1#)) `iShiftL#` 18#) +#
+ (ord# (indexCharOffAddr# addr (nh +# 2#)) `iShiftL#` 12#) +#
+ (ord# (indexCharOffAddr# addr (nh +# 3#)) `iShiftL#` 6#) +#
+ (ord# (indexCharOffAddr# addr (nh +# 4#))) -# 0x2082080#))
+ : unpack (nh +# 5#)
+ | otherwise = C# (chr# (((ord# ch -# 0xFC#) `iShiftL#` 30#) +#
+ ((ord# (indexCharOffAddr# addr (nh +# 1#)) -# 0x80#)
+ `iShiftL#` 24#) +#
+ (ord# (indexCharOffAddr# addr (nh +# 2#)) `iShiftL#` 18#) +#
+ (ord# (indexCharOffAddr# addr (nh +# 3#)) `iShiftL#` 12#) +#
+ (ord# (indexCharOffAddr# addr (nh +# 4#)) `iShiftL#` 6#) +#
+ (ord# (indexCharOffAddr# addr (nh +# 5#))) -# 0x2082080#))
+ : unpack (nh +# 6#)
+ where
+ ch = indexCharOffAddr# addr nh
+
+unpackNBytes# :: Addr# -> Int# -> [Char]
+unpackNBytes# _addr 0# = []
+unpackNBytes# addr len# = unpack [] (len# -# 1#)
+ where
+ unpack acc i#
+ | i# <# 0# = acc
+ | otherwise =
+ case indexCharOffAddr# addr i# of
+ ch -> unpack (C# ch : acc) (i# -# 1#)
+
+{-# RULES
+"unpack" forall a . unpackCString# a = build (unpackFoldrCString# a)
+"unpack-list" forall a . unpackFoldrCString# a (:) [] = unpackCStringList# a
+"unpack-append" forall a n . unpackFoldrCString# a (:) n = unpackAppendCString# a n
+
+-- There's a built-in rule (in PrelRules.lhs) for
+-- unpackFoldr "foo" c (unpackFoldr "baz" c n) = unpackFoldr "foobaz" c n
+
+ #-}
+
+\end{code}
projects / ghc-hetmet.git / blobdiff