[project @ 2001-05-21 14:04:15 by simonmar]

[ghc-hetmet.git] / ghc / lib / std / PrelNum.lhs

diff --git a/ghc/lib/std/PrelNum.lhs b/ghc/lib/std/PrelNum.lhs
index 281ff76..42ec20b 100644 (file)
--- a/ghc/lib/std/PrelNum.lhs
+++ b/ghc/lib/std/PrelNum.lhs
@@ -1,5 +1,5 @@
 % ------------------------------------------------------------------------------
-% $Id: PrelNum.lhs,v 1.36 2001/02/22 16:48:24 qrczak Exp $
+% $Id: PrelNum.lhs,v 1.39 2001/04/14 22:28:22 qrczak Exp $
 %
 % (c) The University of Glasgow, 1994-2000
 %
@@ -49,20 +49,9 @@ class  (Eq a, Show a) => Num a  where
     x - y              = x + negate y
     negate x           = 0 - x
 
-fromInt :: Num a => Int -> a
--- For backward compatibility
-fromInt (I# i#) = fromInteger (S# i#)
-\end{code}
-
-A few small numeric functions
-
-\begin{code}
-subtract       :: (Num a) => a -> a -> a
 {-# INLINE subtract #-}
-subtract x y   =  y - x
-
-ord_0 :: Int
-ord_0 = ord '0'
+subtract :: (Num a) => a -> a -> a
+subtract x y = y - x
 \end{code}
 
 
@@ -74,17 +63,17 @@ ord_0 = ord '0'
 
 \begin{code}
 instance  Num Int  where
-    (+)           x y =  plusInt x y
-    (-)           x y =  minusInt x y
-    negate x   =  negateInt x
-    (*)           x y =  timesInt x y
-    abs    n   = if n `geInt` 0 then n else (negateInt n)
+    (+)           = plusInt
+    (-)           = minusInt
+    negate = negateInt
+    (*)           = timesInt
+    abs n  = if n `geInt` 0 then n else negateInt n
 
     signum n | n `ltInt` 0 = negateInt 1
             | n `eqInt` 0 = 0
             | otherwise   = 1
 
-    fromInteger n = integer2Int n
+    fromInteger = integer2Int
 \end{code}
 
 
@@ -178,7 +167,7 @@ remInteger ia@(S# _) ib@(J# _ _) = remInteger (toBig ia) ib
 remInteger (J# sa a) (S# b)
   = case int2Integer# b of { (# sb, b #) ->
     case remInteger# sa a sb b of { (# sr, r #) ->
-    S# (sr *# (word2Int# (integer2Word# sr r))) }}
+    S# (integer2Int# sr r) }}
 remInteger (J# sa a) (J# sb b)
   = case remInteger# sa a sb b of (# sr, r #) -> J# sr r
 
@@ -235,7 +224,7 @@ divExact :: Integer -> Integer -> Integer
 divExact a@(S# (-2147483648#)) b = divExact (toBig a) b
 divExact (S# a) (S# b) = S# (quotInt# a b)
 divExact (S# a) (J# sb b)
-  = S# (quotInt# a (sb *# (word2Int# (integer2Word# sb b))))
+  = S# (quotInt# a (integer2Int# sb b))
 divExact (J# sa a) (S# b)
   = case int2Integer# b of
      (# sb, b #) -> case divExactInteger# sa a sb b of (# sd, d #) -> J# sd d
@@ -436,24 +425,23 @@ dn_list x delta lim = go (x::Integer)
 %*********************************************************
 
 \begin{code}
-instance  Show Integer  where
-    showsPrec   x = showSignedInteger x
-    showList = showList__ (showsPrec 0) 
-
-showSignedInteger :: Int -> Integer -> ShowS
-showSignedInteger p n r
-  | n < 0 && p > 6 = '(':jtos n (')':r)
-  | otherwise      = jtos n r
+instance Show Integer where
+    showsPrec p n r
+        | n < 0 && p > 6 = '(' : jtos n (')' : r)
+        | otherwise      = jtos n r
+    showList = showList__ (showsPrec 0)
 
 jtos :: Integer -> String -> String
-jtos i rs
- | i < 0     = '-' : jtos' (-i) rs
- | otherwise = jtos' i rs
- where
-  jtos' :: Integer -> String -> String
-  jtos' n cs
-   | n < 10    = chr (fromInteger n + (ord_0::Int)) : cs
-   | otherwise = jtos' q (chr (integer2Int r + (ord_0::Int)) : cs)
+jtos n cs
+    | n < 0     = '-' : jtos' (-n) cs
+    | otherwise = jtos' n cs
     where
-     (q,r) = n `quotRemInteger` 10
+    jtos' :: Integer -> String -> String
+    jtos' n' cs'
+        | n' < 10    = case unsafeChr (ord '0' + fromInteger n') of
+            c@(C# _) -> c:cs'
+        | otherwise = case unsafeChr (ord '0' + fromInteger r) of
+            c@(C# _) -> jtos' q (c:cs')
+        where
+        (q,r) = n' `quotRemInteger` 10
 \end{code}