\begin{code}
-{-# OPTIONS -fno-implicit-prelude #-}
+{-# OPTIONS_GHC -fno-implicit-prelude #-}
+{-# OPTIONS_HADDOCK hide #-}
-----------------------------------------------------------------------------
-- |
-- Module : GHC.Enum
--
-----------------------------------------------------------------------------
+-- #hide
module GHC.Enum(
Bounded(..), Enum(..),
boundedEnumFrom, boundedEnumFromThen,
) where
-import {-# SOURCE #-} GHC.Err ( error )
import GHC.Base
import Data.Tuple () -- for dependencies
default () -- Double isn't available yet
fromEnum () = zeroInt
enumFrom () = [()]
- enumFromThen () () = [()]
+ enumFromThen () () = let many = ():many in many
enumFromTo () () = [()]
- enumFromThenTo () () () = [()]
+ enumFromThenTo () () () = let many = ():many in many
\end{code}
\begin{code}
+-- Report requires instances up to 15
instance (Bounded a, Bounded b) => Bounded (a,b) where
minBound = (minBound, minBound)
maxBound = (maxBound, maxBound)
instance (Bounded a, Bounded b, Bounded c, Bounded d) => Bounded (a,b,c,d) where
minBound = (minBound, minBound, minBound, minBound)
maxBound = (maxBound, maxBound, maxBound, maxBound)
+
+instance (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e) => Bounded (a,b,c,d,e) where
+ minBound = (minBound, minBound, minBound, minBound, minBound)
+ maxBound = (maxBound, maxBound, maxBound, maxBound, maxBound)
+
+instance (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f)
+ => Bounded (a,b,c,d,e,f) where
+ minBound = (minBound, minBound, minBound, minBound, minBound, minBound)
+ maxBound = (maxBound, maxBound, maxBound, maxBound, maxBound, maxBound)
+
+instance (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g)
+ => Bounded (a,b,c,d,e,f,g) where
+ minBound = (minBound, minBound, minBound, minBound, minBound, minBound, minBound)
+ maxBound = (maxBound, maxBound, maxBound, maxBound, maxBound, maxBound, maxBound)
+
+instance (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g,
+ Bounded h)
+ => Bounded (a,b,c,d,e,f,g,h) where
+ minBound = (minBound, minBound, minBound, minBound, minBound, minBound, minBound, minBound)
+ maxBound = (maxBound, maxBound, maxBound, maxBound, maxBound, maxBound, maxBound, maxBound)
+
+instance (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g,
+ Bounded h, Bounded i)
+ => Bounded (a,b,c,d,e,f,g,h,i) where
+ minBound = (minBound, minBound, minBound, minBound, minBound, minBound, minBound, minBound,
+ minBound)
+ maxBound = (maxBound, maxBound, maxBound, maxBound, maxBound, maxBound, maxBound, maxBound,
+ maxBound)
+
+instance (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g,
+ Bounded h, Bounded i, Bounded j)
+ => Bounded (a,b,c,d,e,f,g,h,i,j) where
+ minBound = (minBound, minBound, minBound, minBound, minBound, minBound, minBound, minBound,
+ minBound, minBound)
+ maxBound = (maxBound, maxBound, maxBound, maxBound, maxBound, maxBound, maxBound, maxBound,
+ maxBound, maxBound)
+
+instance (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g,
+ Bounded h, Bounded i, Bounded j, Bounded k)
+ => Bounded (a,b,c,d,e,f,g,h,i,j,k) where
+ minBound = (minBound, minBound, minBound, minBound, minBound, minBound, minBound, minBound,
+ minBound, minBound, minBound)
+ maxBound = (maxBound, maxBound, maxBound, maxBound, maxBound, maxBound, maxBound, maxBound,
+ maxBound, maxBound, maxBound)
+
+instance (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g,
+ Bounded h, Bounded i, Bounded j, Bounded k, Bounded l)
+ => Bounded (a,b,c,d,e,f,g,h,i,j,k,l) where
+ minBound = (minBound, minBound, minBound, minBound, minBound, minBound, minBound, minBound,
+ minBound, minBound, minBound, minBound)
+ maxBound = (maxBound, maxBound, maxBound, maxBound, maxBound, maxBound, maxBound, maxBound,
+ maxBound, maxBound, maxBound, maxBound)
+
+instance (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g,
+ Bounded h, Bounded i, Bounded j, Bounded k, Bounded l, Bounded m)
+ => Bounded (a,b,c,d,e,f,g,h,i,j,k,l,m) where
+ minBound = (minBound, minBound, minBound, minBound, minBound, minBound, minBound, minBound,
+ minBound, minBound, minBound, minBound, minBound)
+ maxBound = (maxBound, maxBound, maxBound, maxBound, maxBound, maxBound, maxBound, maxBound,
+ maxBound, maxBound, maxBound, maxBound, maxBound)
+
+instance (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g,
+ Bounded h, Bounded i, Bounded j, Bounded k, Bounded l, Bounded m, Bounded n)
+ => Bounded (a,b,c,d,e,f,g,h,i,j,k,l,m,n) where
+ minBound = (minBound, minBound, minBound, minBound, minBound, minBound, minBound, minBound,
+ minBound, minBound, minBound, minBound, minBound, minBound)
+ maxBound = (maxBound, maxBound, maxBound, maxBound, maxBound, maxBound, maxBound, maxBound,
+ maxBound, maxBound, maxBound, maxBound, maxBound, maxBound)
+
+instance (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g,
+ Bounded h, Bounded i, Bounded j, Bounded k, Bounded l, Bounded m, Bounded n, Bounded o)
+ => Bounded (a,b,c,d,e,f,g,h,i,j,k,l,m,n,o) where
+ minBound = (minBound, minBound, minBound, minBound, minBound, minBound, minBound, minBound,
+ minBound, minBound, minBound, minBound, minBound, minBound, minBound)
+ maxBound = (maxBound, maxBound, maxBound, maxBound, maxBound, maxBound, maxBound, maxBound,
+ maxBound, maxBound, maxBound, maxBound, maxBound, maxBound, maxBound)
\end{code}
-- Watch out for y=maxBound; hence ==, not >
-- Be very careful not to have more than one "c"
-- so that when eftInfFB is inlined we can inline
- -- whatver is bound to "c"
+ -- whatever is bound to "c"
-----------------------------------------------------
--- efdInt and efdtInt deal with [a,b..] and [a,b..c], which are much less common
--- so we are less elaborate. The code is more complicated anyway, because
--- of worries about Int overflow, so we don't both with rules and deforestation
+-- efdInt and efdtInt deal with [a,b..] and [a,b..c].
+-- The code is more complicated because of worries about Int overflow.
+
+{-# RULES
+"efdtInt" [~1] forall x1 x2 y.
+ efdtInt x1 x2 y = build (\ c n -> efdtIntFB c n x1 x2 y)
+"efdtIntUpList" [1] efdtIntFB (:) [] = efdtInt
+ #-}
efdInt :: Int# -> Int# -> [Int]
-- [x1,x2..maxInt]
efdInt x1 x2
- | x2 >=# x1 = case maxInt of I# y -> efdtIntUp x1 x2 y
- | otherwise = case minInt of I# y -> efdtIntDn x1 x2 y
+ | x2 >=# x1 = case maxInt of I# y -> efdtIntUp x1 x2 y
+ | otherwise = case minInt of I# y -> efdtIntDn x1 x2 y
efdtInt :: Int# -> Int# -> Int# -> [Int]
-- [x1,x2..y]
efdtInt x1 x2 y
- | x2 >=# x1 = efdtIntUp x1 x2 y
- | otherwise = efdtIntDn x1 x2 y
+ | x2 >=# x1 = efdtIntUp x1 x2 y
+ | otherwise = efdtIntDn x1 x2 y
+
+{-# INLINE [0] efdtIntFB #-}
+efdtIntFB :: (Int -> r -> r) -> r -> Int# -> Int# -> Int# -> r
+efdtIntFB c n x1 x2 y
+ | x2 >=# x1 = efdtIntUpFB c n x1 x2 y
+ | otherwise = efdtIntDnFB c n x1 x2 y
+-- Requires x2 >= x1
efdtIntUp :: Int# -> Int# -> Int# -> [Int]
-efdtIntUp x1 x2 y -- Be careful about overflow!
- | y <# x2 = if y <# x1 then [] else [I# x1]
- | otherwise
- = -- Common case: x1 < x2 <= y
- let
- delta = x2 -# x1
- y' = y -# delta
- -- NB: x1 <= y'; hence y' is representable
-
- -- Invariant: x <= y; and x+delta won't overflow
- go_up x | x ># y' = [I# x]
- | otherwise = I# x : go_up (x +# delta)
- in
- I# x1 : go_up x2
-
+efdtIntUp x1 x2 y -- Be careful about overflow!
+ | y <# x2 = if y <# x1 then [] else [I# x1]
+ | otherwise = -- Common case: x1 <= x2 <= y
+ let delta = x2 -# x1 -- >= 0
+ y' = y -# delta -- x1 <= y' <= y; hence y' is representable
+
+ -- Invariant: x <= y
+ -- Note that: z <= y' => z + delta won't overflow
+ -- so we are guaranteed not to overflow if/when we recurse
+ go_up x | x ># y' = [I# x]
+ | otherwise = I# x : go_up (x +# delta)
+ in I# x1 : go_up x2
+
+-- Requires x2 >= x1
+efdtIntUpFB :: (Int -> r -> r) -> r -> Int# -> Int# -> Int# -> r
+efdtIntUpFB c n x1 x2 y -- Be careful about overflow!
+ | y <# x2 = if y <# x1 then n else I# x1 `c` n
+ | otherwise = -- Common case: x1 <= x2 <= y
+ let delta = x2 -# x1 -- >= 0
+ y' = y -# delta -- x1 <= y' <= y; hence y' is representable
+
+ -- Invariant: x <= y
+ -- Note that: z <= y' => z + delta won't overflow
+ -- so we are guaranteed not to overflow if/when we recurse
+ go_up x | x ># y' = I# x `c` n
+ | otherwise = I# x `c` go_up (x +# delta)
+ in I# x1 `c` go_up x2
+
+-- Requires x2 <= x1
efdtIntDn :: Int# -> Int# -> Int# -> [Int]
-efdtIntDn x1 x2 y -- x2 < x1
- | y ># x2 = if y ># x1 then [] else [I# x1]
- | otherwise
- = -- Common case: x1 > x2 >= y
- let
- delta = x2 -# x1
- y' = y -# delta
- -- NB: x1 <= y'; hence y' is representable
-
- -- Invariant: x >= y; and x+delta won't overflow
- go_dn x | x <# y' = [I# x]
- | otherwise = I# x : go_dn (x +# delta)
- in
- I# x1 : go_dn x2
+efdtIntDn x1 x2 y -- Be careful about underflow!
+ | y ># x2 = if y ># x1 then [] else [I# x1]
+ | otherwise = -- Common case: x1 >= x2 >= y
+ let delta = x2 -# x1 -- <= 0
+ y' = y -# delta -- y <= y' <= x1; hence y' is representable
+
+ -- Invariant: x >= y
+ -- Note that: z >= y' => z + delta won't underflow
+ -- so we are guaranteed not to underflow if/when we recurse
+ go_dn x | x <# y' = [I# x]
+ | otherwise = I# x : go_dn (x +# delta)
+ in I# x1 : go_dn x2
+
+-- Requires x2 <= x1
+efdtIntDnFB :: (Int -> r -> r) -> r -> Int# -> Int# -> Int# -> r
+efdtIntDnFB c n x1 x2 y -- Be careful about underflow!
+ | y ># x2 = if y ># x1 then n else I# x1 `c` n
+ | otherwise = -- Common case: x1 >= x2 >= y
+ let delta = x2 -# x1 -- <= 0
+ y' = y -# delta -- y <= y' <= x1; hence y' is representable
+
+ -- Invariant: x >= y
+ -- Note that: z >= y' => z + delta won't underflow
+ -- so we are guaranteed not to underflow if/when we recurse
+ go_dn x | x <# y' = I# x `c` n
+ | otherwise = I# x `c` go_dn (x +# delta)
+ in I# x1 `c` go_dn x2
\end{code}
projects / ghc-base.git / blobdiff