+% -----------------------------------------------------------------------------
+% $Id: Array.lhs,v 1.16 2001/04/14 22:27:00 qrczak Exp $
%
-% (c) The AQUA Project, Glasgow University, 1994-1996
+% (c) The University of Glasgow, 1994-2000
%
-
\section[Array]{Module @Array@}
\begin{code}
{-# OPTIONS -fno-implicit-prelude #-}
-module Array (
- module Ix, -- export all of Ix
- Array, -- Array type is abstract
+module Array
+
+ (
+ module Ix -- export all of Ix
+ , Array -- Array type is abstract
+
+ , array -- :: (Ix a) => (a,a) -> [(a,b)] -> Array a b
+ , listArray -- :: (Ix a) => (a,a) -> [b] -> Array a b
+ , (!) -- :: (Ix a) => Array a b -> a -> b
+ , bounds -- :: (Ix a) => Array a b -> (a,a)
+ , indices -- :: (Ix a) => Array a b -> [a]
+ , elems -- :: (Ix a) => Array a b -> [b]
+ , assocs -- :: (Ix a) => Array a b -> [(a,b)]
+ , accumArray -- :: (Ix a) => (b -> c -> b) -> b -> (a,a) -> [(a,c)] -> Array a b
+ , (//) -- :: (Ix a) => Array a b -> [(a,b)] -> Array a b
+ , accum -- :: (Ix a) => (b -> c -> b) -> Array a b -> [(a,c)] -> Array a b
+ , ixmap -- :: (Ix a, Ix b) => (a,a) -> (a -> b) -> Array b c -> Array a b
+
+ -- Array instances:
+ --
+ -- Ix a => Functor (Array a)
+ -- (Ix a, Eq b) => Eq (Array a b)
+ -- (Ix a, Ord b) => Ord (Array a b)
+ -- (Ix a, Show a, Show b) => Show (Array a b)
+ -- (Ix a, Read a, Read b) => Read (Array a b)
+ --
+
+ -- Implementation checked wrt. Haskell 98 lib report, 1/99.
+
+ ) where
+\end{code}
- array, listArray, (!), bounds, indices, elems, assocs,
- accumArray, (//), accum, ixmap
- ) where
+#ifndef __HUGS__
+\begin{code}
+ ------------ GHC --------------------
import Ix
-import PrelList
-import PrelRead
import PrelArr -- Most of the hard work is done here
-import PrelBase
+ ------------ End of GHC --------------------
+\end{code}
+
+#else
+
+\begin{code}
+ ------------ HUGS (rest of file) --------------------
+import PrelPrim ( PrimArray
+ , runST
+ , primNewArray
+ , primWriteArray
+ , primReadArray
+ , primUnsafeFreezeArray
+ , primIndexArray
+ )
+import Ix
+import List( (\\) )
infixl 9 !, //
\end{code}
-
%*********************************************************
%* *
-\subsection{Definitions of array, !, bounds}
+\subsection{The Array type}
%* *
%*********************************************************
+
\begin{code}
+data Array ix elt = Array (ix,ix) (PrimArray elt)
-#ifdef USE_FOLDR_BUILD
-{-# INLINE indices #-}
-{-# INLINE elems #-}
-{-# INLINE assocs #-}
-#endif
+array :: Ix a => (a,a) -> [(a,b)] -> Array a b
+array ixs@(ix_start, ix_end) ivs = runST (do
+ { mut_arr <- primNewArray (rangeSize ixs) arrEleBottom
+ ; mapM_ (\ (i,v) -> primWriteArray mut_arr (index ixs i) v) ivs
+ ; arr <- primUnsafeFreezeArray mut_arr
+ ; return (Array ixs arr)
+ }
+ )
+ where
+ arrEleBottom = error "(Array.!): undefined array element"
-{-# SPECIALISE listArray :: (Int,Int) -> [b] -> Array Int b #-}
-listArray :: (Ix a) => (a,a) -> [b] -> Array a b
-listArray b vs = array b (zipWith (\ a b -> (a,b)) (range b) vs)
+listArray :: Ix a => (a,a) -> [b] -> Array a b
+listArray b vs = array b (zipWith (\ a b -> (a,b)) (range b) vs)
-{-# SPECIALISE indices :: Array Int b -> [Int] #-}
-indices :: (Ix a) => Array a b -> [a]
-indices = range . bounds
+(!) :: Ix a => Array a b -> a -> b
+(Array bounds arr) ! i = primIndexArray arr (index bounds i)
-{-# SPECIALISE elems :: Array Int b -> [b] #-}
-elems :: (Ix a) => Array a b -> [b]
-elems a = [a!i | i <- indices a]
+bounds :: Ix a => Array a b -> (a,a)
+bounds (Array b _) = b
-{-# SPECIALISE assocs :: Array Int b -> [(Int,b)] #-}
-assocs :: (Ix a) => Array a b -> [(a,b)]
-assocs a = [(i, a!i) | i <- indices a]
+indices :: Ix a => Array a b -> [a]
+indices = range . bounds
-{-# SPECIALISE amap :: (b -> c) -> Array Int b -> Array Int c #-}
-amap :: (Ix a) => (b -> c) -> Array a b -> Array a c
-amap f a = array b [(i, f (a!i)) | i <- range b]
- where b = bounds a
+elems :: Ix a => Array a b -> [b]
+elems a = [a!i | i <- indices a]
-ixmap :: (Ix a, Ix b) => (a,a) -> (a -> b) -> Array b c -> Array a c
-ixmap b f a = array b [(i, a ! f i) | i <- range b]
-\end{code}
+assocs :: Ix a => Array a b -> [(a,b)]
+assocs a = [(i, a!i) | i <- indices a]
+(//) :: Ix a => Array a b -> [(a,b)] -> Array a b
+(//) a us = array (bounds a)
+ ([(i,a!i) | i <- indices a \\ [i | (i,_) <- us]]
+ ++ us)
-%*********************************************************
-%* *
-\subsection{Instance declarations for Array type}
-%* *
-%*********************************************************
+accum :: Ix a => (b -> c -> b) -> Array a b -> [(a,c)] -> Array a b
+accum f = foldl (\a (i,v) -> a // [(i,f (a!i) v)])
-\begin{code}
-instance Ix a => Functor (Array a) where
- map = amap
+accumArray :: Ix a => (b -> c -> b) -> b -> (a,a) -> [(a,c)] -> Array a b
+accumArray f z b = accum f (array b [(i,z) | i <- range b])
+
+ixmap :: (Ix a, Ix b) => (a,a) -> (a -> b) -> Array b c -> Array a c
+ixmap b f a = array b [(i, a ! f i) | i <- range b]
-instance (Ix a, Eq b) => Eq (Array a b) where
- a == a' = assocs a == assocs a'
- a /= a' = assocs a /= assocs a'
-instance (Ix a, Ord b) => Ord (Array a b) where
- compare a b = compare (assocs a) (assocs b)
+instance (Ix a) => Functor (Array a) where
+ fmap f a = array (bounds a) [(i, f(a!i)) | i <- indices a]
+
+instance (Ix a, Eq b) => Eq (Array a b) where
+ a == a' = assocs a == assocs a'
+
+instance (Ix a, Ord b) => Ord (Array a b) where
+ a <= a' = assocs a <= assocs a'
+
instance (Ix a, Show a, Show b) => Show (Array a b) where
showsPrec p a = showParen (p > 9) (
showString "array " .
shows (bounds a) . showChar ' ' .
shows (assocs a) )
- showList = showList__ (showsPrec 0)
instance (Ix a, Read a, Read b) => Read (Array a b) where
readsPrec p = readParen (p > 9)
- (\r -> [(array b as, u) | ("array",s) <- lex r,
- (b,t) <- reads s,
- (as,u) <- reads t ])
- readList = readList__ (readsPrec 0)
+ (\r -> [(array b as, u) | ("array",s) <- lex r,
+ (b,t) <- reads s,
+ (as,u) <- reads t ])
+
\end{code}
+#endif
projects / ghc-hetmet.git / blobdiff