module GHC.Arr (
Ix(..), Array(..), STArray(..),
arrEleBottom, array, listArray,
(!), safeRangeSize, negRange, safeIndex, badSafeIndex,
bounds, numElements, numElementsSTArray, indices, elems,
assocs, accumArray, adjust, (//), accum,
amap, ixmap,
eqArray, cmpArray, cmpIntArray,
newSTArray, boundsSTArray,
readSTArray, writeSTArray,
freezeSTArray, thawSTArray,
foldlElems, foldlElems', foldl1Elems,
foldrElems, foldrElems', foldr1Elems,
fill, done,
unsafeArray, unsafeArray',
lessSafeIndex, unsafeAt, unsafeReplace,
unsafeAccumArray, unsafeAccumArray', unsafeAccum,
unsafeReadSTArray, unsafeWriteSTArray,
unsafeFreezeSTArray, unsafeThawSTArray,
) where
import GHC.Num
import GHC.ST
import GHC.Base
import GHC.List
import GHC.Ix
import GHC.Show
infixl 9 !, //
default ()
data Array i e
= Array !i
!i
!Int
(Array# e)
data STArray s i e
= STArray !i
!i
!Int
(MutableArray# s e)
type role Array nominal representational
type role STArray nominal nominal representational
instance Eq (STArray s i e) where
STArray _ _ _ arr1# == STArray _ _ _ arr2# =
isTrue# (sameMutableArray# arr1# arr2#)
arrEleBottom :: a
arrEleBottom = errorWithoutStackTrace "(Array.!): undefined array element"
array :: Ix i
=> (i,i)
-> [(i, e)]
-> Array i e
array (l,u) ies
= let n = safeRangeSize (l,u)
in unsafeArray' (l,u) n
[(safeIndex (l,u) n i, e) | (i, e) <- ies]
unsafeArray :: Ix i => (i,i) -> [(Int, e)] -> Array i e
unsafeArray b ies = unsafeArray' b (rangeSize b) ies
unsafeArray' :: (i,i) -> Int -> [(Int, e)] -> Array i e
unsafeArray' (l,u) n@(I# n#) ies = runST (ST $ \s1# ->
case newArray# n# arrEleBottom s1# of
(# s2#, marr# #) ->
foldr (fill marr#) (done l u n marr#) ies s2#)
fill :: MutableArray# s e -> (Int, e) -> STRep s a -> STRep s a
fill marr# (I# i#, e) next
= \s1# -> case writeArray# marr# i# e s1# of
s2# -> next s2#
done :: i -> i -> Int -> MutableArray# s e -> STRep s (Array i e)
done l u n@(I# _) marr#
= \s1# -> case unsafeFreezeArray# marr# s1# of
(# s2#, arr# #) -> (# s2#, Array l u n arr# #)
listArray :: Ix i => (i,i) -> [e] -> Array i e
listArray (l,u) es = runST (ST $ \s1# ->
case safeRangeSize (l,u) of { n@(I# n#) ->
case newArray# n# arrEleBottom s1# of { (# s2#, marr# #) ->
let
go y r = \ i# s3# ->
case writeArray# marr# i# y s3# of
s4# -> if (isTrue# (i# ==# n# -# 1#))
then s4#
else r (i# +# 1#) s4#
in
done l u n marr# (
if n == 0
then s2#
else foldr go (\_ s# -> s#) es 0# s2#)}})
(!) :: Ix i => Array i e -> i -> e
(!) arr@(Array l u n _) i = unsafeAt arr $ safeIndex (l,u) n i
(!#) :: Ix i => Array i e -> i -> (# e #)
(!#) arr@(Array l u n _) i = unsafeAt# arr $ safeIndex (l,u) n i
safeRangeSize :: Ix i => (i, i) -> Int
safeRangeSize (l,u) = let r = rangeSize (l, u)
in if r < 0 then negRange
else r
negRange :: Int
negRange = errorWithoutStackTrace "Negative range size"
safeIndex :: Ix i => (i, i) -> Int -> i -> Int
safeIndex (l,u) n@(I# _) i
| (0 <= i') && (i' < n) = i'
| otherwise = badSafeIndex i' n
where
i' = index (l,u) i
lessSafeIndex :: Ix i => (i, i) -> Int -> i -> Int
lessSafeIndex (l,u) _ i = index (l,u) i
badSafeIndex :: Int -> Int -> Int
badSafeIndex i' n = errorWithoutStackTrace ("Error in array index; " ++ show i' ++
" not in range [0.." ++ show n ++ ")")
unsafeAt :: Array i e -> Int -> e
unsafeAt (Array _ _ _ arr#) (I# i#) =
case indexArray# arr# i# of (# e #) -> e
unsafeAt# :: Array i e -> Int -> (# e #)
unsafeAt# (Array _ _ _ arr#) (I# i#) = indexArray# arr# i#
unsafeAtA :: Applicative f
=> Array i e -> Int -> f e
unsafeAtA ary i = case unsafeAt# ary i of (# e #) -> pure e
bounds :: Array i e -> (i,i)
bounds (Array l u _ _) = (l,u)
numElements :: Array i e -> Int
numElements (Array _ _ n _) = n
indices :: Ix i => Array i e -> [i]
indices (Array l u _ _) = range (l,u)
elems :: Array i e -> [e]
elems arr@(Array _ _ n _) =
[e | i <- [0 .. n 1], e <- unsafeAtA arr i]
foldrElems :: (a -> b -> b) -> b -> Array i a -> b
foldrElems f b0 = \ arr@(Array _ _ n _) ->
let
go i | i == n = b0
| (# e #) <- unsafeAt# arr i
= f e (go (i+1))
in go 0
foldlElems :: (b -> a -> b) -> b -> Array i a -> b
foldlElems f b0 = \ arr@(Array _ _ n _) ->
let
go i | i == (1) = b0
| (# e #) <- unsafeAt# arr i
= f (go (i1)) e
in go (n1)
foldrElems' :: (a -> b -> b) -> b -> Array i a -> b
foldrElems' f b0 = \ arr@(Array _ _ n _) ->
let
go i a | i == (1) = a
| (# e #) <- unsafeAt# arr i
= go (i1) (f e $! a)
in go (n1) b0
foldlElems' :: (b -> a -> b) -> b -> Array i a -> b
foldlElems' f b0 = \ arr@(Array _ _ n _) ->
let
go i a | i == n = a
| (# e #) <- unsafeAt# arr i
= go (i+1) (a `seq` f a e)
in go 0 b0
foldl1Elems :: (a -> a -> a) -> Array i a -> a
foldl1Elems f = \ arr@(Array _ _ n _) ->
let
go i | i == 0 = unsafeAt arr 0
| (# e #) <- unsafeAt# arr i
= f (go (i1)) e
in
if n == 0 then errorWithoutStackTrace "foldl1: empty Array" else go (n1)
foldr1Elems :: (a -> a -> a) -> Array i a -> a
foldr1Elems f = \ arr@(Array _ _ n _) ->
let
go i | i == n1 = unsafeAt arr i
| (# e #) <- unsafeAt# arr i
= f e (go (i + 1))
in
if n == 0 then errorWithoutStackTrace "foldr1: empty Array" else go 0
assocs :: Ix i => Array i e -> [(i, e)]
assocs arr@(Array l u _ _) =
[(i, e) | i <- range (l,u), let !(# e #) = arr !# i]
accumArray :: Ix i
=> (e -> a -> e)
-> e
-> (i,i)
-> [(i, a)]
-> Array i e
accumArray f initial (l,u) ies =
let n = safeRangeSize (l,u)
in unsafeAccumArray' f initial (l,u) n
[(safeIndex (l,u) n i, e) | (i, e) <- ies]
unsafeAccumArray :: Ix i => (e -> a -> e) -> e -> (i,i) -> [(Int, a)] -> Array i e
unsafeAccumArray f initial b ies = unsafeAccumArray' f initial b (rangeSize b) ies
unsafeAccumArray' :: (e -> a -> e) -> e -> (i,i) -> Int -> [(Int, a)] -> Array i e
unsafeAccumArray' f initial (l,u) n@(I# n#) ies = runST (ST $ \s1# ->
case newArray# n# initial s1# of { (# s2#, marr# #) ->
foldr (adjust' f marr#) (done l u n marr#) ies s2# })
adjust :: (e -> a -> e) -> MutableArray# s e -> (Int, a) -> STRep s b -> STRep s b
adjust f marr# (I# i#, new) next
= \s1# -> case readArray# marr# i# s1# of
(# s2#, old #) ->
case writeArray# marr# i# (f old new) s2# of
s3# -> next s3#
adjust' :: (e -> a -> e)
-> MutableArray# s e
-> (Int, a)
-> STRep s b -> STRep s b
adjust' f marr# (I# i#, new) next
= \s1# -> case readArray# marr# i# s1# of
(# s2#, old #) ->
let !combined = f old new
in next (writeArray# marr# i# combined s2#)
(//) :: Ix i => Array i e -> [(i, e)] -> Array i e
arr@(Array l u n _) // ies =
unsafeReplace arr [(safeIndex (l,u) n i, e) | (i, e) <- ies]
unsafeReplace :: Array i e -> [(Int, e)] -> Array i e
unsafeReplace arr ies = runST (do
STArray l u n marr# <- thawSTArray arr
ST (foldr (fill marr#) (done l u n marr#) ies))
accum :: Ix i => (e -> a -> e) -> Array i e -> [(i, a)] -> Array i e
accum f arr@(Array l u n _) ies =
unsafeAccum f arr [(safeIndex (l,u) n i, e) | (i, e) <- ies]
unsafeAccum :: (e -> a -> e) -> Array i e -> [(Int, a)] -> Array i e
unsafeAccum f arr ies = runST (do
STArray l u n marr# <- thawSTArray arr
ST (foldr (adjust' f marr#) (done l u n marr#) ies))
amap :: (a -> b) -> Array i a -> Array i b
amap f arr@(Array l u n@(I# n#) _) = runST (ST $ \s1# ->
case newArray# n# arrEleBottom s1# of
(# s2#, marr# #) ->
let go i s#
| i == n = done l u n marr# s#
| (# e #) <- unsafeAt# arr i
= fill marr# (i, f e) (go (i+1)) s#
in go 0 s2# )
ixmap :: (Ix i, Ix j) => (i,i) -> (i -> j) -> Array j e -> Array i e
ixmap (l,u) f arr =
array (l,u) [(i, arr ! f i) | i <- range (l,u)]
eqArray :: (Ix i, Eq e) => Array i e -> Array i e -> Bool
eqArray arr1@(Array l1 u1 n1 _) arr2@(Array l2 u2 n2 _) =
if n1 == 0 then n2 == 0 else
l1 == l2 && u1 == u2 &&
and [unsafeAt arr1 i == unsafeAt arr2 i | i <- [0 .. n1 1]]
cmpArray :: (Ix i, Ord e) => Array i e -> Array i e -> Ordering
cmpArray arr1 arr2 = compare (assocs arr1) (assocs arr2)
cmpIntArray :: Ord e => Array Int e -> Array Int e -> Ordering
cmpIntArray arr1@(Array l1 u1 n1 _) arr2@(Array l2 u2 n2 _) =
if n1 == 0 then
if n2 == 0 then EQ else LT
else if n2 == 0 then GT
else case compare l1 l2 of
EQ -> foldr cmp (compare u1 u2) [0 .. (n1 `min` n2) 1]
other -> other
where
cmp i rest = case compare (unsafeAt arr1 i) (unsafeAt arr2 i) of
EQ -> rest
other -> other
instance Functor (Array i) where
fmap = amap
x <$ Array l u n@(I# n#) _ =
runST $ ST $ \s1# ->
case newArray# n# x s1# of
(# s2#, marr# #) -> done l u n marr# s2#
instance (Ix i, Eq e) => Eq (Array i e) where
(==) = eqArray
instance (Ix i, Ord e) => Ord (Array i e) where
compare = cmpArray
instance (Ix a, Show a, Show b) => Show (Array a b) where
showsPrec p a =
showParen (p > appPrec) $
showString "array " .
showsPrec appPrec1 (bounds a) .
showChar ' ' .
showsPrec appPrec1 (assocs a)
newSTArray :: Ix i => (i,i) -> e -> ST s (STArray s i e)
newSTArray (l,u) initial = ST $ \s1# ->
case safeRangeSize (l,u) of { n@(I# n#) ->
case newArray# n# initial s1# of { (# s2#, marr# #) ->
(# s2#, STArray l u n marr# #) }}
boundsSTArray :: STArray s i e -> (i,i)
boundsSTArray (STArray l u _ _) = (l,u)
numElementsSTArray :: STArray s i e -> Int
numElementsSTArray (STArray _ _ n _) = n
readSTArray :: Ix i => STArray s i e -> i -> ST s e
readSTArray marr@(STArray l u n _) i =
unsafeReadSTArray marr (safeIndex (l,u) n i)
unsafeReadSTArray :: STArray s i e -> Int -> ST s e
unsafeReadSTArray (STArray _ _ _ marr#) (I# i#)
= ST $ \s1# -> readArray# marr# i# s1#
writeSTArray :: Ix i => STArray s i e -> i -> e -> ST s ()
writeSTArray marr@(STArray l u n _) i e =
unsafeWriteSTArray marr (safeIndex (l,u) n i) e
unsafeWriteSTArray :: STArray s i e -> Int -> e -> ST s ()
unsafeWriteSTArray (STArray _ _ _ marr#) (I# i#) e = ST $ \s1# ->
case writeArray# marr# i# e s1# of
s2# -> (# s2#, () #)
freezeSTArray :: STArray s i e -> ST s (Array i e)
freezeSTArray (STArray l u n@(I# n#) marr#) = ST $ \s1# ->
case newArray# n# arrEleBottom s1# of { (# s2#, marr'# #) ->
let copy i# s3# | isTrue# (i# ==# n#) = s3#
| otherwise =
case readArray# marr# i# s3# of { (# s4#, e #) ->
case writeArray# marr'# i# e s4# of { s5# ->
copy (i# +# 1#) s5# }} in
case copy 0# s2# of { s3# ->
case unsafeFreezeArray# marr'# s3# of { (# s4#, arr# #) ->
(# s4#, Array l u n arr# #) }}}
unsafeFreezeSTArray :: STArray s i e -> ST s (Array i e)
unsafeFreezeSTArray (STArray l u n marr#) = ST $ \s1# ->
case unsafeFreezeArray# marr# s1# of { (# s2#, arr# #) ->
(# s2#, Array l u n arr# #) }
thawSTArray :: Array i e -> ST s (STArray s i e)
thawSTArray (Array l u n@(I# n#) arr#) = ST $ \s1# ->
case newArray# n# arrEleBottom s1# of { (# s2#, marr# #) ->
let copy i# s3# | isTrue# (i# ==# n#) = s3#
| otherwise =
case indexArray# arr# i# of { (# e #) ->
case writeArray# marr# i# e s3# of { s4# ->
copy (i# +# 1#) s4# }} in
case copy 0# s2# of { s3# ->
(# s3#, STArray l u n marr# #) }}
unsafeThawSTArray :: Array i e -> ST s (STArray s i e)
unsafeThawSTArray (Array l u n arr#) = ST $ \s1# ->
case unsafeThawArray# arr# s1# of { (# s2#, marr# #) ->
(# s2#, STArray l u n marr# #) }