X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=GHC%2FExts.hs;h=81a9dbb4edb399c29d2fb9fc1e96053332f39572;hb=41e8fba828acbae1751628af50849f5352b27873;hp=7869c4788ac7b8935527eeb60a58e08823153d7e;hpb=848e9b5b80d5e25a2120011c4ac7b38ac4e557f8;p=ghc-base.git

diff --git a/GHC/Exts.hs b/GHC/Exts.hs
index 7869c47..81a9dbb 100644
--- a/GHC/Exts.hs
+++ b/GHC/Exts.hs
@@ -1,3 +1,5 @@
+{-# LANGUAGE MagicHash, UnboxedTuples, DeriveDataTypeable #-}
+
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  GHC.Exts
@@ -15,29 +17,39 @@
 module GHC.Exts
        (
         -- * Representations of some basic types
-        Int(..),Word(..),Float(..),Double(..),Integer(..),Char(..),
-	Ptr(..), FunPtr(..),
+        Int(..),Word(..),Float(..),Double(..),
+        Char(..),
+        Ptr(..), FunPtr(..),
+
+        -- * The maximum tuple size
+        maxTupleSize,
 
         -- * Primitive operations
         module GHC.Prim,
-	shiftL#, shiftRL#, iShiftL#, iShiftRA#, iShiftRL#,
+        shiftL#, shiftRL#, iShiftL#, iShiftRA#, iShiftRL#,
         uncheckedShiftL64#, uncheckedShiftRL64#,
         uncheckedIShiftL64#, uncheckedIShiftRA64#,
 
-	-- * Fusion
-	build, augment,
+        -- * Fusion
+        build, augment,
 
-	-- * Overloaded string literals
-	IsString(..),
+        -- * Overloaded string literals
+        IsString(..),
 
-	-- * Debugging
-	breakpoint, breakpointCond,
+        -- * Debugging
+        breakpoint, breakpointCond,
 
-	-- * Ids with special behaviour
-	lazy, inline,
+        -- * Ids with special behaviour
+        lazy, inline,
 
         -- * Transform comprehensions
-        groupWith, sortWith, the
+        Down(..), groupWith, sortWith, the,
+
+        -- * Event logging
+        traceEvent,
+
+        -- * SpecConstr annotations
+        SpecConstrAnnotation(..)
 
        ) where
 
@@ -45,18 +57,35 @@ import Prelude
 
 import GHC.Prim
 import GHC.Base
+import GHC.Magic
 import GHC.Word
 import GHC.Int
-import GHC.Num
-import GHC.Float
+-- import GHC.Float
 import GHC.Ptr
 import Data.String
 import Data.List
+import Foreign.C
+import Data.Data
+
+-- XXX This should really be in Data.Tuple, where the definitions are
+maxTupleSize :: Int
+maxTupleSize = 62
+
+-- | The 'Down' type allows you to reverse sort order conveniently.  A value of type
+-- @'Down' a@ contains a value of type @a@ (represented as @'Down' a@).
+-- If @a@ has an @'Ord'@ instance associated with it then comparing two
+-- values thus wrapped will give you the opposite of their normal sort order.
+-- This is particularly useful when sorting in generalised list comprehensions,
+-- as in: @then sortWith by 'Down' x@
+newtype Down a = Down a deriving (Eq)
+
+instance Ord a => Ord (Down a) where
+    compare (Down x) (Down y) = y `compare` x
 
 -- | 'the' ensures that all the elements of the list are identical
 -- and then returns that unique element
 the :: Eq a => [a] -> a
-the (x:xs) 
+the (x:xs)
   | all (x ==) xs = x
   | otherwise     = error "GHC.Exts.the: non-identical elements"
 the []            = error "GHC.Exts.the: empty list"
@@ -69,5 +98,40 @@ sortWith f = sortBy (\x y -> compare (f x) (f y))
 -- | The 'groupWith' function uses the user supplied function which
 -- projects an element out of every list element in order to to first sort the 
 -- input list and then to form groups by equality on these projected elements
+{-# INLINE groupWith #-}
 groupWith :: Ord b => (a -> b) -> [a] -> [[a]]
-groupWith f = groupBy (\x y -> f x == f y) . sortWith f
+groupWith f xs = build (\c n -> groupByFB c n (\x y -> f x == f y) (sortWith f xs))
+
+groupByFB :: ([a] -> lst -> lst) -> lst -> (a -> a -> Bool) -> [a] -> lst
+groupByFB c n eq xs0 = groupByFBCore xs0
+  where groupByFBCore [] = n
+        groupByFBCore (x:xs) = c (x:ys) (groupByFBCore zs)
+            where (ys, zs) = span (eq x) xs
+
+
+-- -----------------------------------------------------------------------------
+-- tracing
+
+traceEvent :: String -> IO ()
+traceEvent msg = do
+  withCString msg $ \(Ptr p) -> IO $ \s ->
+    case traceEvent# p s of s' -> (# s', () #)
+
+
+
+{- **********************************************************************
+*									*
+*              SpecConstr annotation                                    *
+*									*
+********************************************************************** -}
+
+-- Annotating a type with NoSpecConstr will make SpecConstr 
+-- not specialise for arguments of that type.
+
+-- This data type is defined here, rather than in the SpecConstr module
+-- itself, so that importing it doesn't force stupidly linking the
+-- entire ghc package at runtime
+
+data SpecConstrAnnotation = NoSpecConstr | ForceSpecConstr
+                deriving( Data, Typeable, Eq )
+