Add Data and Typeable instances to HsSyn

[ghc-hetmet.git] / compiler / utils / Util.lhs

diff --git a/compiler/utils/Util.lhs b/compiler/utils/Util.lhs
index 37aedc8..fbbe767 100644 (file)
--- a/compiler/utils/Util.lhs
+++ b/compiler/utils/Util.lhs
@@ -7,7 +7,7 @@
 -- | Highly random utility functions
 module Util (
         -- * Flags dependent on the compiler build
-        ghciSupported, debugIsOn, ghciTablesNextToCode, picIsOn,
+        ghciSupported, debugIsOn, ghciTablesNextToCode, isDynamicGhcLib,
         isWindowsHost, isWindowsTarget, isDarwinTarget,
 
         -- * General list processing
@@ -30,6 +30,9 @@ module Util (
 
         isIn, isn'tIn,
 
+        -- * Tuples
+        fstOf3, sndOf3, thirdOf3,
+
         -- * List operations controlled by another list
         takeList, dropList, splitAtList, split,
         dropTail,
@@ -73,20 +76,22 @@ module Util (
         escapeSpaces,
         parseSearchPath,
         Direction(..), reslash,
+
+        -- * Utils for defining Data instances
+        abstractConstr, abstractDataType, mkNoRepType
     ) where
 
 #include "HsVersions.h"
 
 import Panic
 
-import Data.IORef       ( IORef, newIORef )
+import Data.Data
+import Data.IORef       ( IORef, newIORef, atomicModifyIORef )
 import System.IO.Unsafe ( unsafePerformIO )
-import Data.IORef       ( readIORef, writeIORef )
 import Data.List        hiding (group)
 import Control.Concurrent.MVar ( MVar, newMVar, newEmptyMVar )
 
 #ifdef DEBUG
-import qualified Data.List as List ( elem, notElem )
 import FastTypes
 #endif
 
@@ -139,11 +144,11 @@ ghciTablesNextToCode = True
 ghciTablesNextToCode = False
 #endif
 
-picIsOn :: Bool
-#ifdef __PIC__
-picIsOn = True
+isDynamicGhcLib :: Bool
+#ifdef DYNAMIC
+isDynamicGhcLib = True
 #else
-picIsOn = False
+isDynamicGhcLib = False
 #endif
 
 isWindowsHost :: Bool
@@ -182,6 +187,15 @@ nTimes 1 f = f
 nTimes n f = f . nTimes (n-1) f
 \end{code}
 
+\begin{code}
+fstOf3   :: (a,b,c) -> a    
+sndOf3   :: (a,b,c) -> b    
+thirdOf3 :: (a,b,c) -> c    
+fstOf3      (a,_,_) =  a
+sndOf3      (_,b,_) =  b
+thirdOf3    (_,_,c) =  c
+\end{code}
+
 %************************************************************************
 %*                                                                      *
 \subsection[Utils-lists]{General list processing}
@@ -387,36 +401,27 @@ Debugging/specialising versions of \tr{elem} and \tr{notElem}
 isIn, isn'tIn :: Eq a => String -> a -> [a] -> Bool
 
 # ifndef DEBUG
-isIn    _msg x ys = elem__    x ys
-isn'tIn _msg x ys = notElem__ x ys
-
---these are here to be SPECIALIZEd (automagically)
-elem__ :: Eq a => a -> [a] -> Bool
-elem__ _ []     = False
-elem__ x (y:ys) = x == y || elem__ x ys
-
-notElem__ :: Eq a => a -> [a] -> Bool
-notElem__ _ []     = True
-notElem__ x (y:ys) = x /= y && notElem__ x ys
+isIn    _msg x ys = x `elem` ys
+isn'tIn _msg x ys = x `notElem` ys
 
 # else /* DEBUG */
 isIn msg x ys
-  = elem (_ILIT(0)) x ys
+  = elem100 (_ILIT(0)) x ys
   where
-    elem _ _ []        = False
-    elem i x (y:ys)
+    elem100 _ _ []        = False
+    elem100 i x (y:ys)
       | i ># _ILIT(100) = trace ("Over-long elem in " ++ msg)
-                                (x `List.elem` (y:ys))
-      | otherwise       = x == y || elem (i +# _ILIT(1)) x ys
+                                (x `elem` (y:ys))
+      | otherwise       = x == y || elem100 (i +# _ILIT(1)) x ys
 
 isn'tIn msg x ys
-  = notElem (_ILIT(0)) x ys
+  = notElem100 (_ILIT(0)) x ys
   where
-    notElem _ _ [] =  True
-    notElem i x (y:ys)
+    notElem100 _ _ [] =  True
+    notElem100 i x (y:ys)
       | i ># _ILIT(100) = trace ("Over-long notElem in " ++ msg)
-                                (x `List.notElem` (y:ys))
-      | otherwise      =  x /= y && notElem (i +# _ILIT(1)) x ys
+                                (x `notElem` (y:ys))
+      | otherwise      =  x /= y && notElem100 (i +# _ILIT(1)) x ys
 # endif /* DEBUG */
 \end{code}
 
@@ -696,8 +701,7 @@ global a = unsafePerformIO (newIORef a)
 \begin{code}
 consIORef :: IORef [a] -> a -> IO ()
 consIORef var x = do
-  xs <- readIORef var
-  writeIORef var (x:xs)
+  atomicModifyIORef var (\xs -> (x:xs,()))
 \end{code}
 
 \begin{code}
@@ -902,3 +906,29 @@ reslash d = f
                   Backwards -> '\\'
 \end{code}
 
+%************************************************************************
+%*                                                                      *
+\subsection[Utils-Data]{Utils for defining Data instances}
+%*                                                                      *
+%************************************************************************
+
+These functions helps us to define Data instances for abstract types.
+
+\begin{code}
+abstractConstr :: String -> Constr
+abstractConstr n = mkConstr (abstractDataType n) ("{abstract:"++n++"}") [] Prefix
+\end{code}
+
+\begin{code}
+abstractDataType :: String -> DataType
+abstractDataType n = mkDataType n [abstractConstr n]
+\end{code}
+
+\begin{code}
+-- Old GHC versions come with a base library with this function misspelled.
+#if __GLASGOW_HASKELL__ < 612
+mkNoRepType :: String -> DataType
+mkNoRepType = mkNorepType
+#endif
+\end{code}
+