[project @ 1996-01-08 20:28:12 by partain]

[ghc-hetmet.git] / ghc / lib / hbc / Number.hs

diff --git a/ghc/lib/hbc/Number.hs b/ghc/lib/hbc/Number.hs
new file mode 100644 (file)
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--- /dev/null
+++ b/ghc/lib/hbc/Number.hs
@@ -0,0 +1,124 @@
+module Number(Number, isInteger) where
+data Number = I Integer | F Double
+
+toF (I i) = fromInteger i
+toF (F f) = f
+
+toI (I i) = i
+toI (F f) = round f
+
+-- slow!!
+toN x | fromInteger i == x = I i where i = truncate x
+toN x = F x
+
+isInteger (I i) = True
+isInteger (F x) = fromInteger (truncate x) == x
+
+instance Eq Number where
+    I x == I y = x == y
+    x   == y   = toF x == toF y
+
+instance Ord Number where
+    I x <= I y = x <= y
+    x   <= y   = toF x <= toF y
+
+instance Text Number where
+    showsPrec p (I i) = showsPrec p i
+--    showsPrec p (F f) | fromInteger i == f = showsPrec p i where i = truncate f
+    showsPrec p (F f) = 
+        let s = reverse (show f)
+           s' = if 'e' `notElem` s then dropWhile (=='0') (tail s) else s
+           s'' = if head s' == '.' then tail s' else s'
+       in  showString (reverse s'')
+    readsPrec p s = [(I i, s) | (i, s)<-readsPrec p s] ++
+                    [(F i, s) | (i, s)<-readsPrec p s]
+
+#if defined(__HBC__)
+    showsType _ = showString "Number"
+#endif
+
+instance Num Number where
+    I x + I y  = I (x+y)
+    x   + y    = toN (toF x + toF y)
+    I x - I y  = I (x-y)
+    x   - y    = toN (toF x - toF y)
+    I x * I y  = I (x*y)
+    x   * y    = toN (toF x * toF y)
+    negate (I x) = I (-x)
+    negate (F x) = F (-x)
+    abs x = if x <= 0 then -x else x
+    signum x = if x <= 0 then if x==0 then 0 else -1 else 1
+    fromInteger i = I i
+
+instance Ix Number where
+    range (x, y) = [I i | i<-[toI x .. toI y]]
+    index (x, y) i = fromInteger (toI i - toI x)
+    inRange (x, y) i = toI x <= toI i && toI i <= toI y
+
+instance Integral Number where
+    quotRem (I x) (I y) = case quotRem x y of (q,r) -> (I q, I r)
+    quotRem x y = let q = truncate (x' / y')
+                      x' = toF x
+                     y' = toF y
+                  in  (I q, toN (x' - fromInteger q * y'))
+    toInteger (I i) = i
+    toInteger (F f) = round f
+
+instance Enum Number where
+    enumFrom (I i) = [I x | x<-[i..]]
+    enumFrom (F i) = [F x | x<-[i..]]
+    enumFromThen (I i) (I j) = [I x | x<-[i,j..]]
+    enumFromThen i j = [F x | x<-[toF i,toF j..]]
+
+instance Real Number where
+    toRational (I i) = i % 1
+    toRational (F f) = toRational f
+
+instance Fractional Number where
+    I x / I y | r == 0 = I q where (q,r) = quotRem x y
+    x / y = toN (toF x / toF y)
+    fromRational r | denominator r == 0 = I (numerator r)
+    fromRational r = toN (fromRational r)
+
+instance RealFrac Number where
+    properFraction (I i) = (fromInteger i, I 0)
+    properFraction (F f) = let (i,x) = properFraction f in (i, toN x)
+    truncate (I i) = fromInteger i
+    truncate (F f) = truncate f
+    round (I i) = fromInteger i
+    round (F f) = round f
+    ceiling (I i) = fromInteger i
+    ceiling (F f) = ceiling f
+    floor (I i) = fromInteger i
+    floor (F f) = floor f
+
+instance RealFloat Number where
+    floatRadix x = floatRadix (toF x)
+    floatDigits x = floatDigits (toF x)
+    floatRange x = floatRange (toF x)
+    decodeFloat x = decodeFloat (toF x)
+    encodeFloat m e = toN (encodeFloat m e)
+    exponent x = exponent (toF x)
+    significand x = toN (significand (toF x))
+    scaleFloat n x = toN (scaleFloat n (toF x))
+
+instance Floating Number where
+    pi = F pi
+    exp = toN . exp . toF
+    log = toN . log . toF
+    sqrt = toN . sqrt . toF
+    x ** y = toN (toF x ** toF y)
+    logBase x y = toN (logBase (toF x) (toF y))
+    sin = toN . sin . toF
+    cos = toN . cos . toF
+    tan = toN . tan . toF
+    asin = toN . asin . toF
+    acos = toN . acos . toF
+    atan = toN . atan . toF
+    sinh = toN . sinh . toF
+    cosh = toN . cosh . toF
+    tanh = toN . tanh . toF
+    asinh = toN . asinh . toF
+    acosh = toN . acosh . toF
+    atanh = toN . atanh . toF
+