2 % (c) The AQUA Project, Glasgow University, 1994-1999
5 \section[Array]{Module @Array@}
8 {-# OPTIONS -fno-implicit-prelude #-}
13 module Ix -- export all of Ix
14 , Array -- Array type is abstract
16 , array -- :: (Ix a) => (a,a) -> [(a,b)] -> Array a b
17 , listArray -- :: (Ix a) => (a,a) -> [b] -> Array a b
18 , (!) -- :: (Ix a) => Array a b -> a -> b
19 , bounds -- :: (Ix a) => Array a b -> (a,a)
20 , indices -- :: (Ix a) => Array a b -> [a]
21 , elems -- :: (Ix a) => Array a b -> [b]
22 , assocs -- :: (Ix a) => Array a b -> [(a,b)]
23 , accumArray -- :: (Ix a) => (b -> c -> b) -> b -> (a,a) -> [(a,c)] -> Array a b
24 , (//) -- :: (Ix a) => Array a b -> [(a,b)] -> Array a b
25 , accum -- :: (Ix a) => (b -> c -> b) -> Array a b -> [(a,c)] -> Array a b
26 , ixmap -- :: (Ix a, Ix b) => (a,a) -> (a -> b) -> Array b c -> Array a b
30 -- Ix a => Functor (Array a)
31 -- (Ix a, Eq b) => Eq (Array a b)
32 -- (Ix a, Ord b) => Ord (Array a b)
33 -- (Ix a, Show a, Show b) => Show (Array a b)
34 -- (Ix a, Read a, Read b) => Read (Array a b)
37 -- Implementation checked wrt. Haskell 98 lib report, 1/99.
44 import PrelArr -- Most of the hard work is done here
52 %*********************************************************
54 \subsection{Definitions of array, !, bounds}
56 %*********************************************************
60 #ifdef USE_FOLDR_BUILD
61 {-# INLINE indices #-}
66 {-# SPECIALISE listArray :: (Int,Int) -> [b] -> Array Int b #-}
67 listArray :: (Ix a) => (a,a) -> [b] -> Array a b
68 listArray b vs = array b (zip (range b) vs)
70 {-# SPECIALISE indices :: Array Int b -> [Int] #-}
71 indices :: (Ix a) => Array a b -> [a]
72 indices = range . bounds
74 {-# SPECIALISE elems :: Array Int b -> [b] #-}
75 elems :: (Ix a) => Array a b -> [b]
76 elems a = [a!i | i <- indices a]
78 {-# SPECIALISE assocs :: Array Int b -> [(Int,b)] #-}
79 assocs :: (Ix a) => Array a b -> [(a,b)]
80 assocs a = [(i, a!i) | i <- indices a]
82 {-# SPECIALISE amap :: (b -> c) -> Array Int b -> Array Int c #-}
83 amap :: (Ix a) => (b -> c) -> Array a b -> Array a c
84 amap f a = array b [(i, f (a!i)) | i <- range b]
87 ixmap :: (Ix a, Ix b) => (a,a) -> (a -> b) -> Array b c -> Array a c
88 ixmap b f a = array b [(i, a ! f i) | i <- range b]
92 %*********************************************************
94 \subsection{Instance declarations for Array type}
96 %*********************************************************
99 instance Ix a => Functor (Array a) where
102 instance (Ix a, Eq b) => Eq (Array a b) where
103 a == a' = assocs a == assocs a'
104 a /= a' = assocs a /= assocs a'
106 instance (Ix a, Ord b) => Ord (Array a b) where
107 compare a b = compare (assocs a) (assocs b)
109 instance (Ix a, Show a, Show b) => Show (Array a b) where
110 showsPrec p a = showParen (p > 9) (
111 showString "array " .
112 shows (bounds a) . showChar ' ' .
114 showList = showList__ (showsPrec 0)
117 instance (Ix a, Read a, Read b) => Read (Array a b) where
118 readsPrec p = readParen (p > 9)
119 (\r -> [(array b as, u) | ("array",s) <- lex r,
122 readList = readList__ (readsPrec 0)