1 % ------------------------------------------------------------------------------
2 % $Id: PrelNum.lhs,v 1.32 2000/06/30 13:39:36 simonmar Exp $
4 % (c) The University of Glasgow, 1994-2000
7 \section[PrelNum]{Module @PrelNum@}
19 {-# OPTIONS -fno-implicit-prelude #-}
23 import {-# SOURCE #-} PrelErr
32 default () -- Double isn't available yet,
33 -- and we shouldn't be using defaults anyway
36 %*********************************************************
38 \subsection{Standard numeric class}
40 %*********************************************************
43 class (Eq a, Show a) => Num a where
44 (+), (-), (*) :: a -> a -> a
47 fromInteger :: Integer -> a
48 fromInt :: Int -> a -- partain: Glasgow extension
52 fromInt (I# i#) = fromInteger (S# i#)
53 -- Go via the standard class-op if the
54 -- non-standard one ain't provided
57 A few small numeric functions
60 subtract :: (Num a) => a -> a -> a
61 {-# INLINE subtract #-}
65 ord_0 = fromInt (ord '0')
69 %*********************************************************
71 \subsection{Instances for @Int@}
73 %*********************************************************
76 instance Num Int where
78 (-) x y = minusInt x y
79 negate x = negateInt x
80 (*) x y = timesInt x y
81 abs n = if n `geInt` 0 then n else (negateInt n)
83 signum n | n `ltInt` 0 = negateInt 1
87 fromInteger n = integer2Int n
93 -- These can't go in PrelBase with the defn of Int, because
94 -- we don't have pairs defined at that time!
96 quotRemInt :: Int -> Int -> (Int, Int)
97 a@(I# _) `quotRemInt` b@(I# _) = (a `quotInt` b, a `remInt` b)
98 -- OK, so I made it a little stricter. Shoot me. (WDP 94/10)
100 divModInt :: Int -> Int -> (Int, Int)
101 divModInt x@(I# _) y@(I# _) = (x `divInt` y, x `modInt` y)
102 -- Stricter. Sorry if you don't like it. (WDP 94/10)
106 %*********************************************************
108 \subsection{The @Integer@ type}
110 %*********************************************************
114 = S# Int# -- small integers
115 | J# Int# ByteArray# -- large integers
118 Convenient boxed Integer PrimOps.
121 zeroInteger :: Integer
124 int2Integer :: Int -> Integer
125 {-# INLINE int2Integer #-}
126 int2Integer (I# i) = S# i
128 integer2Int :: Integer -> Int
129 integer2Int (S# i) = I# i
130 integer2Int (J# s d) = case (integer2Int# s d) of { n# -> I# n# }
132 addr2Integer :: Addr# -> Integer
133 {-# INLINE addr2Integer #-}
134 addr2Integer x = case addr2Integer# x of (# s, d #) -> J# s d
136 toBig (S# i) = case int2Integer# i of { (# s, d #) -> J# s d }
141 %*********************************************************
143 \subsection{Dividing @Integers@}
145 %*********************************************************
148 quotRemInteger :: Integer -> Integer -> (Integer, Integer)
149 quotRemInteger a@(S# (-2147483648#)) b = quotRemInteger (toBig a) b
150 quotRemInteger (S# i) (S# j)
151 = case quotRemInt (I# i) (I# j) of ( I# i, I# j ) -> ( S# i, S# j )
152 quotRemInteger i1@(J# _ _) i2@(S# _) = quotRemInteger i1 (toBig i2)
153 quotRemInteger i1@(S# _) i2@(J# _ _) = quotRemInteger (toBig i1) i2
154 quotRemInteger (J# s1 d1) (J# s2 d2)
155 = case (quotRemInteger# s1 d1 s2 d2) of
157 -> (J# s3 d3, J# s4 d4)
159 divModInteger a@(S# (-2147483648#)) b = divModInteger (toBig a) b
160 divModInteger (S# i) (S# j)
161 = case divModInt (I# i) (I# j) of ( I# i, I# j ) -> ( S# i, S# j)
162 divModInteger i1@(J# _ _) i2@(S# _) = divModInteger i1 (toBig i2)
163 divModInteger i1@(S# _) i2@(J# _ _) = divModInteger (toBig i1) i2
164 divModInteger (J# s1 d1) (J# s2 d2)
165 = case (divModInteger# s1 d1 s2 d2) of
167 -> (J# s3 d3, J# s4 d4)
169 remInteger :: Integer -> Integer -> Integer
171 = error "Prelude.Integral.rem{Integer}: divide by 0"
172 remInteger a@(S# (-2147483648#)) b = remInteger (toBig a) b
173 remInteger (S# a) (S# b) = S# (remInt# a b)
174 {- Special case doesn't work, because a 1-element J# has the range
175 -(2^32-1) -- 2^32-1, whereas S# has the range -2^31 -- (2^31-1)
176 remInteger ia@(S# a) (J# sb b)
177 | sb ==# 1# = S# (remInt# a (word2Int# (integer2Word# sb b)))
178 | sb ==# -1# = S# (remInt# a (0# -# (word2Int# (integer2Word# sb b))))
180 | otherwise = S# (0# -# a)
182 remInteger ia@(S# _) ib@(J# _ _) = remInteger (toBig ia) ib
183 remInteger (J# sa a) (S# b)
184 = case int2Integer# b of { (# sb, b #) ->
185 case remInteger# sa a sb b of { (# sr, r #) ->
186 S# (sr *# (word2Int# (integer2Word# sr r))) }}
187 remInteger (J# sa a) (J# sb b)
188 = case remInteger# sa a sb b of (# sr, r #) -> J# sr r
190 quotInteger :: Integer -> Integer -> Integer
192 = error "Prelude.Integral.quot{Integer}: divide by 0"
193 quotInteger a@(S# (-2147483648#)) b = quotInteger (toBig a) b
194 quotInteger (S# a) (S# b) = S# (quotInt# a b)
195 {- Special case disabled, see remInteger above
196 quotInteger (S# a) (J# sb b)
197 | sb ==# 1# = S# (quotInt# a (word2Int# (integer2Word# sb b)))
198 | sb ==# -1# = S# (quotInt# a (0# -# (word2Int# (integer2Word# sb b))))
199 | otherwise = zeroInteger
201 quotInteger ia@(S# _) ib@(J# _ _) = quotInteger (toBig ia) ib
202 quotInteger (J# sa a) (S# b)
203 = case int2Integer# b of { (# sb, b #) ->
204 case quotInteger# sa a sb b of (# sq, q #) -> J# sq q }
205 quotInteger (J# sa a) (J# sb b)
206 = case quotInteger# sa a sb b of (# sg, g #) -> J# sg g
212 gcdInteger :: Integer -> Integer -> Integer
213 -- SUP: Do we really need the first two cases?
214 gcdInteger a@(S# (-2147483648#)) b = gcdInteger (toBig a) b
215 gcdInteger a b@(S# (-2147483648#)) = gcdInteger a (toBig b)
216 gcdInteger (S# a) (S# b) = case gcdInt (I# a) (I# b) of { I# c -> S# c }
217 gcdInteger ia@(S# 0#) ib@(J# 0# _) = error "PrelNum.gcdInteger: gcd 0 0 is undefined"
218 gcdInteger ia@(S# a) ib@(J# sb b)
221 | otherwise = S# (gcdIntegerInt# absSb b absA)
222 where absA = if a <# 0# then negateInt# a else a
223 absSb = if sb <# 0# then negateInt# sb else sb
224 gcdInteger ia@(J# _ _) ib@(S# _) = gcdInteger ib ia
225 gcdInteger (J# 0# _) (J# 0# _) = error "PrelNum.gcdInteger: gcd 0 0 is undefined"
226 gcdInteger (J# sa a) (J# sb b)
227 = case gcdInteger# sa a sb b of (# sg, g #) -> J# sg g
229 lcmInteger :: Integer -> Integer -> Integer
235 = (divExact aa (gcdInteger aa ab)) * ab
239 divExact :: Integer -> Integer -> Integer
240 divExact a@(S# (-2147483648#)) b = divExact (toBig a) b
241 divExact (S# a) (S# b) = S# (quotInt# a b)
242 divExact (S# a) (J# sb b)
243 = S# (quotInt# a (sb *# (word2Int# (integer2Word# sb b))))
244 divExact (J# sa a) (S# b)
245 = case int2Integer# b of
246 (# sb, b #) -> case divExactInteger# sa a sb b of (# sd, d #) -> J# sd d
247 divExact (J# sa a) (J# sb b)
248 = case divExactInteger# sa a sb b of (# sd, d #) -> J# sd d
252 %*********************************************************
254 \subsection{The @Integer@ instances for @Eq@, @Ord@}
256 %*********************************************************
259 instance Eq Integer where
260 (S# i) == (S# j) = i ==# j
261 (S# i) == (J# s d) = cmpIntegerInt# s d i ==# 0#
262 (J# s d) == (S# i) = cmpIntegerInt# s d i ==# 0#
263 (J# s1 d1) == (J# s2 d2) = (cmpInteger# s1 d1 s2 d2) ==# 0#
265 (S# i) /= (S# j) = i /=# j
266 (S# i) /= (J# s d) = cmpIntegerInt# s d i /=# 0#
267 (J# s d) /= (S# i) = cmpIntegerInt# s d i /=# 0#
268 (J# s1 d1) /= (J# s2 d2) = (cmpInteger# s1 d1 s2 d2) /=# 0#
270 ------------------------------------------------------------------------
271 instance Ord Integer where
272 (S# i) <= (S# j) = i <=# j
273 (J# s d) <= (S# i) = cmpIntegerInt# s d i <=# 0#
274 (S# i) <= (J# s d) = cmpIntegerInt# s d i >=# 0#
275 (J# s1 d1) <= (J# s2 d2) = (cmpInteger# s1 d1 s2 d2) <=# 0#
277 (S# i) > (S# j) = i ># j
278 (J# s d) > (S# i) = cmpIntegerInt# s d i ># 0#
279 (S# i) > (J# s d) = cmpIntegerInt# s d i <# 0#
280 (J# s1 d1) > (J# s2 d2) = (cmpInteger# s1 d1 s2 d2) ># 0#
282 (S# i) < (S# j) = i <# j
283 (J# s d) < (S# i) = cmpIntegerInt# s d i <# 0#
284 (S# i) < (J# s d) = cmpIntegerInt# s d i ># 0#
285 (J# s1 d1) < (J# s2 d2) = (cmpInteger# s1 d1 s2 d2) <# 0#
287 (S# i) >= (S# j) = i >=# j
288 (J# s d) >= (S# i) = cmpIntegerInt# s d i >=# 0#
289 (S# i) >= (J# s d) = cmpIntegerInt# s d i <=# 0#
290 (J# s1 d1) >= (J# s2 d2) = (cmpInteger# s1 d1 s2 d2) >=# 0#
292 compare (S# i) (S# j)
296 compare (J# s d) (S# i)
297 = case cmpIntegerInt# s d i of { res# ->
298 if res# <# 0# then LT else
299 if res# ># 0# then GT else EQ
301 compare (S# i) (J# s d)
302 = case cmpIntegerInt# s d i of { res# ->
303 if res# ># 0# then LT else
304 if res# <# 0# then GT else EQ
306 compare (J# s1 d1) (J# s2 d2)
307 = case cmpInteger# s1 d1 s2 d2 of { res# ->
308 if res# <# 0# then LT else
309 if res# ># 0# then GT else EQ
314 %*********************************************************
316 \subsection{The @Integer@ instances for @Num@}
318 %*********************************************************
321 instance Num Integer where
322 (+) i1@(S# i) i2@(S# j)
323 = case addIntC# i j of { (# r, c #) ->
324 if c ==# 0# then S# r
325 else toBig i1 + toBig i2 }
326 (+) i1@(J# _ _) i2@(S# _) = i1 + toBig i2
327 (+) i1@(S# _) i2@(J# _ _) = toBig i1 + i2
328 (+) (J# s1 d1) (J# s2 d2)
329 = case plusInteger# s1 d1 s2 d2 of (# s, d #) -> J# s d
331 (-) i1@(S# i) i2@(S# j)
332 = case subIntC# i j of { (# r, c #) ->
333 if c ==# 0# then S# r
334 else toBig i1 - toBig i2 }
335 (-) i1@(J# _ _) i2@(S# _) = i1 - toBig i2
336 (-) i1@(S# _) i2@(J# _ _) = toBig i1 - i2
337 (-) (J# s1 d1) (J# s2 d2)
338 = case minusInteger# s1 d1 s2 d2 of (# s, d #) -> J# s d
340 (*) i1@(S# i) i2@(S# j)
341 = case mulIntC# i j of { (# r, c #) ->
342 if c ==# 0# then S# r
343 else toBig i1 * toBig i2 }
344 (*) i1@(J# _ _) i2@(S# _) = i1 * toBig i2
345 (*) i1@(S# _) i2@(J# _ _) = toBig i1 * i2
346 (*) (J# s1 d1) (J# s2 d2)
347 = case timesInteger# s1 d1 s2 d2 of (# s, d #) -> J# s d
349 negate (S# (-2147483648#)) = 2147483648
350 negate (S# i) = S# (negateInt# i)
351 negate (J# s d) = J# (negateInt# s) d
353 -- ORIG: abs n = if n >= 0 then n else -n
355 abs (S# (-2147483648#)) = 2147483648
356 abs (S# i) = case abs (I# i) of I# j -> S# j
357 abs n@(J# s d) = if (s >=# 0#) then n else J# (negateInt# s) d
359 signum (S# i) = case signum (I# i) of I# j -> S# j
362 cmp = cmpIntegerInt# s d 0#
364 if cmp ># 0# then S# 1#
365 else if cmp ==# 0# then S# 0#
366 else S# (negateInt# 1#)
370 fromInt (I# i) = S# i
374 %*********************************************************
376 \subsection{The @Integer@ instance for @Enum@}
378 %*********************************************************
381 instance Enum Integer where
384 toEnum n = int2Integer n
385 fromEnum n = integer2Int n
387 {-# INLINE enumFrom #-}
388 {-# INLINE enumFromThen #-}
389 {-# INLINE enumFromTo #-}
390 {-# INLINE enumFromThenTo #-}
391 enumFrom x = efdInteger x 1
392 enumFromThen x y = efdInteger x (y-x)
393 enumFromTo x lim = efdtInteger x 1 lim
394 enumFromThenTo x y lim = efdtInteger x (y-x) lim
397 efdInteger = enumDeltaIntegerList
398 efdtInteger = enumDeltaToIntegerList
401 "efdInteger" forall x y. efdInteger x y = build (\c _ -> enumDeltaIntegerFB c x y)
402 "efdtInteger" forall x y l.efdtInteger x y l = build (\c n -> enumDeltaToIntegerFB c n x y l)
403 "enumDeltaInteger" enumDeltaIntegerFB (:) = enumDeltaIntegerList
404 "enumDeltaToInteger" enumDeltaToIntegerFB (:) [] = enumDeltaToIntegerList
407 enumDeltaIntegerFB :: (Integer -> b -> b) -> Integer -> Integer -> b
408 enumDeltaIntegerFB c x d = x `c` enumDeltaIntegerFB c (x+d) d
410 enumDeltaIntegerList :: Integer -> Integer -> [Integer]
411 enumDeltaIntegerList x d = x : enumDeltaIntegerList (x+d) d
413 enumDeltaToIntegerFB c n x delta lim
414 | delta >= 0 = up_fb c n x delta lim
415 | otherwise = dn_fb c n x delta lim
417 enumDeltaToIntegerList x delta lim
418 | delta >= 0 = up_list x delta lim
419 | otherwise = dn_list x delta lim
421 up_fb c n x delta lim = go (x::Integer)
424 | otherwise = x `c` go (x+delta)
425 dn_fb c n x delta lim = go (x::Integer)
428 | otherwise = x `c` go (x+delta)
430 up_list x delta lim = go (x::Integer)
433 | otherwise = x : go (x+delta)
434 dn_list x delta lim = go (x::Integer)
437 | otherwise = x : go (x+delta)
442 %*********************************************************
444 \subsection{The @Integer@ instances for @Show@}
446 %*********************************************************
449 instance Show Integer where
450 showsPrec x = showSignedInteger x
451 showList = showList__ (showsPrec 0)
453 showSignedInteger :: Int -> Integer -> ShowS
454 showSignedInteger p n r
455 | n < 0 && p > 6 = '(':jtos n (')':r)
456 | otherwise = jtos n r
458 jtos :: Integer -> String -> String
460 | i < 0 = '-' : jtos' (-i) rs
461 | otherwise = jtos' i rs
463 jtos' :: Integer -> String -> String
465 | n < 10 = chr (fromInteger n + (ord_0::Int)) : cs
466 | otherwise = jtos' q (chr (integer2Int r + (ord_0::Int)) : cs)
468 (q,r) = n `quotRemInteger` 10