[project @ 2004-09-30 10:35:15 by simonpj]

------------------------------------
	Add Generalised Algebraic Data Types
	------------------------------------

This rather big commit adds support for GADTs.  For example,

    data Term a where
 	  Lit :: Int -> Term Int
	  App :: Term (a->b) -> Term a -> Term b
	  If  :: Term Bool -> Term a -> Term a
	  ..etc..

    eval :: Term a -> a
    eval (Lit i) = i
    eval (App a b) = eval a (eval b)
    eval (If p q r) | eval p    = eval q
    		    | otherwise = eval r


Lots and lots of of related changes throughout the compiler to make
this fit nicely.

One important change, only loosely related to GADTs, is that skolem
constants in the typechecker are genuinely immutable and constant, so
we often get better error messages from the type checker.  See
TcType.TcTyVarDetails.

There's a new module types/Unify.lhs, which has purely-functional
unification and matching for Type. This is used both in the typechecker
(for type refinement of GADTs) and in Core Lint (also for type refinement).

12 files changed, 19 insertions, 19 deletions

diff --git a/ghc/compiler/codeGen/CgBindery.lhs b/ghc/compiler/codeGen/CgBindery.lhs
index 0f858777c2..5a953500a0 100644
--- a/ghc/compiler/codeGen/CgBindery.lhs
+++ b/ghc/compiler/codeGen/CgBindery.lhs
@@ -258,9 +258,9 @@ cgLookupPanic id
 	pprPanic "cgPanic"
 		(vcat [ppr id,
 		ptext SLIT("static binds for:"),
-		vcat [ ppr (cg_id info) | info <- rngVarEnv static_binds ],
+		vcat [ ppr (cg_id info) | info <- varEnvElts static_binds ],
 		ptext SLIT("local binds for:"),
-		vcat [ ppr (cg_id info) | info <- rngVarEnv local_binds ],
+		vcat [ ppr (cg_id info) | info <- varEnvElts local_binds ],
 	        ptext SLIT("SRT label") <+> pprCLabel srt
 	      ])
 \end{code}
@@ -277,7 +277,7 @@ we don't leave any (NoVolatile, NoStable) binds around...
 \begin{code}
 nukeVolatileBinds :: CgBindings -> CgBindings
 nukeVolatileBinds binds
-  = mkVarEnv (foldr keep_if_stable [] (rngVarEnv binds))
+  = mkVarEnv (foldr keep_if_stable [] (varEnvElts binds))
   where
     keep_if_stable (CgIdInfo { cg_stb = NoStableLoc }) acc = acc
     keep_if_stable info acc
@@ -443,7 +443,7 @@ nukeDeadBindings live_vars = do
 	let (dead_stk_slots, bs') =
 		dead_slots live_vars 
 			[] []
-			[ (cg_id b, b) | b <- rngVarEnv binds ]
+			[ (cg_id b, b) | b <- varEnvElts binds ]
 	setBinds $ mkVarEnv bs'
 	freeStackSlots dead_stk_slots
 \end{code}
@@ -486,6 +486,6 @@ getLiveStackSlots :: FCode [VirtualSpOffset]
 getLiveStackSlots 
   = do 	{ binds <- getBinds
 	; return [off | CgIdInfo { cg_stb = VirStkLoc off, 
-				   cg_rep = rep } <- rngVarEnv binds, 
+				   cg_rep = rep } <- varEnvElts binds, 
 		        isFollowableArg rep] }
 \end{code}
diff --git a/ghc/compiler/codeGen/CgCase.lhs b/ghc/compiler/codeGen/CgCase.lhs
index bdcc5ff17c..bdacd27ebd 100644
--- a/ghc/compiler/codeGen/CgCase.lhs
+++ b/ghc/compiler/codeGen/CgCase.lhs
@@ -1,7 +1,7 @@
 %
 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
 %
-% $Id: CgCase.lhs,v 1.70 2004/08/13 13:25:45 simonmar Exp $
+% $Id: CgCase.lhs,v 1.71 2004/09/30 10:35:36 simonpj Exp $
 %
 %********************************************************
 %*							*
diff --git a/ghc/compiler/codeGen/CgClosure.lhs b/ghc/compiler/codeGen/CgClosure.lhs
index dc5e9eae35..0c6ca4b76f 100644
--- a/ghc/compiler/codeGen/CgClosure.lhs
+++ b/ghc/compiler/codeGen/CgClosure.lhs
@@ -1,7 +1,7 @@
 %
 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
 %
-% $Id: CgClosure.lhs,v 1.63 2004/08/13 13:05:54 simonmar Exp $
+% $Id: CgClosure.lhs,v 1.64 2004/09/30 10:35:39 simonpj Exp $
 %
 \section[CgClosure]{Code generation for closures}
 
diff --git a/ghc/compiler/codeGen/CgCon.lhs b/ghc/compiler/codeGen/CgCon.lhs
index 6b3b36abaa..7dc5d75b41 100644
--- a/ghc/compiler/codeGen/CgCon.lhs
+++ b/ghc/compiler/codeGen/CgCon.lhs
@@ -45,7 +45,7 @@ import CostCentre	( currentOrSubsumedCCS, dontCareCCS, CostCentreStack,
 			  currentCCS )
 import Constants	( mIN_INTLIKE, mAX_INTLIKE, mIN_CHARLIKE, mAX_CHARLIKE )
 import TyCon		( TyCon, tyConDataCons, isEnumerationTyCon, tyConName )
-import DataCon		( DataCon, dataConRepArgTys, isNullaryDataCon,
+import DataCon		( DataCon, dataConRepArgTys, isNullaryRepDataCon,
 			  isUnboxedTupleCon, dataConWorkId, 
 			  dataConName, dataConRepArity
 			)
@@ -404,7 +404,7 @@ static closure, for a constructor.
 cgDataCon :: DataCon -> Code
 cgDataCon data_con
   = do	{     -- Don't need any dynamic closure code for zero-arity constructors
-	  whenC (not (isNullaryDataCon data_con))
+	  whenC (not (isNullaryRepDataCon data_con))
 	 	(emit_info dyn_cl_info tickyEnterDynCon)
 
 		-- Dynamic-Closure first, to reduce forward references
diff --git a/ghc/compiler/codeGen/CgExpr.lhs b/ghc/compiler/codeGen/CgExpr.lhs
index d72c7c5a4c..ff405319c4 100644
--- a/ghc/compiler/codeGen/CgExpr.lhs
+++ b/ghc/compiler/codeGen/CgExpr.lhs
@@ -1,7 +1,7 @@
 %
 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
 %
-% $Id: CgExpr.lhs,v 1.59 2004/08/13 13:05:58 simonmar Exp $
+% $Id: CgExpr.lhs,v 1.60 2004/09/30 10:35:43 simonpj Exp $
 %
 %********************************************************
 %*							*
diff --git a/ghc/compiler/codeGen/CgHeapery.lhs b/ghc/compiler/codeGen/CgHeapery.lhs
index 6abffe72dc..5e6c122f7c 100644
--- a/ghc/compiler/codeGen/CgHeapery.lhs
+++ b/ghc/compiler/codeGen/CgHeapery.lhs
@@ -1,7 +1,7 @@
 %
 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
 %
-% $Id: CgHeapery.lhs,v 1.40 2004/08/13 13:06:00 simonmar Exp $
+% $Id: CgHeapery.lhs,v 1.41 2004/09/30 10:35:45 simonpj Exp $
 %
 \section[CgHeapery]{Heap management functions}
 
diff --git a/ghc/compiler/codeGen/CgLetNoEscape.lhs b/ghc/compiler/codeGen/CgLetNoEscape.lhs
index 3ea05974f6..39860f4ee0 100644
--- a/ghc/compiler/codeGen/CgLetNoEscape.lhs
+++ b/ghc/compiler/codeGen/CgLetNoEscape.lhs
@@ -1,7 +1,7 @@
 %
 % (c) The GRASP/AQUA Project, Glasgow University, 1993-1998
 %
-% $Id: CgLetNoEscape.lhs,v 1.25 2004/08/13 13:06:03 simonmar Exp $
+% $Id: CgLetNoEscape.lhs,v 1.26 2004/09/30 10:35:47 simonpj Exp $
 %
 %********************************************************
 %*							*
diff --git a/ghc/compiler/codeGen/CgProf.hs b/ghc/compiler/codeGen/CgProf.hs
index 30f801dba3..0c2381b14a 100644
--- a/ghc/compiler/codeGen/CgProf.hs
+++ b/ghc/compiler/codeGen/CgProf.hs
@@ -389,9 +389,9 @@ emitSetCCC :: CostCentre -> Code
 emitSetCCC cc
   | not opt_SccProfilingOn = nopC
   | otherwise = do 
-    ASSERTM(sccAbleCostCentre cc)
     tmp <- newTemp wordRep
-    pushCostCentre tmp curCCS cc
+    ASSERT( sccAbleCostCentre cc )
+      pushCostCentre tmp curCCS cc
     stmtC (CmmStore curCCSAddr (CmmReg tmp))
     when (isSccCountCostCentre cc) $ 
 	stmtC (bumpSccCount curCCS)
diff --git a/ghc/compiler/codeGen/CgStackery.lhs b/ghc/compiler/codeGen/CgStackery.lhs
index 2dddb3d34f..7cb310d521 100644
--- a/ghc/compiler/codeGen/CgStackery.lhs
+++ b/ghc/compiler/codeGen/CgStackery.lhs
@@ -1,7 +1,7 @@
 %
 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
 %
-% $Id: CgStackery.lhs,v 1.26 2004/08/17 15:23:48 simonpj Exp $
+% $Id: CgStackery.lhs,v 1.27 2004/09/30 10:35:49 simonpj Exp $
 %
 \section[CgStackery]{Stack management functions}
 
diff --git a/ghc/compiler/codeGen/CgTailCall.lhs b/ghc/compiler/codeGen/CgTailCall.lhs
index 982891b2f7..98c075d31d 100644
--- a/ghc/compiler/codeGen/CgTailCall.lhs
+++ b/ghc/compiler/codeGen/CgTailCall.lhs
@@ -1,7 +1,7 @@
 %
 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
 %
-% $Id: CgTailCall.lhs,v 1.39 2004/08/13 13:06:13 simonmar Exp $
+% $Id: CgTailCall.lhs,v 1.40 2004/09/30 10:35:50 simonpj Exp $
 %
 %********************************************************
 %*							*
diff --git a/ghc/compiler/codeGen/ClosureInfo.lhs b/ghc/compiler/codeGen/ClosureInfo.lhs
index 0abf831c51..476aa2aa95 100644
--- a/ghc/compiler/codeGen/ClosureInfo.lhs
+++ b/ghc/compiler/codeGen/ClosureInfo.lhs
@@ -65,7 +65,7 @@ import CmdLineOpts	( opt_SccProfilingOn, opt_OmitBlackHoling,
 			  opt_Parallel, opt_DoTickyProfiling,
 			  opt_SMP )
 import Id		( Id, idType, idArity, idName )
-import DataCon		( DataCon, dataConTyCon, isNullaryDataCon, dataConName )
+import DataCon		( DataCon, dataConTyCon, isNullaryRepDataCon, dataConName )
 import Name		( Name, nameUnique, getOccName, getOccString )
 import OccName		( occNameUserString )
 import Type		( isUnLiftedType, Type, repType, splitTyConApp_maybe )
@@ -663,7 +663,7 @@ staticClosureNeedsLink :: ClosureInfo -> Bool
 staticClosureNeedsLink (ClosureInfo { closureSRT = srt })
   = needsSRT srt
 staticClosureNeedsLink (ConInfo { closureSMRep = sm_rep, closureCon = con })
-  = not (isNullaryDataCon con) && not_nocaf_constr
+  = not (isNullaryRepDataCon con) && not_nocaf_constr
   where
     not_nocaf_constr = 
 	case sm_rep of 
diff --git a/ghc/compiler/codeGen/CodeGen.lhs b/ghc/compiler/codeGen/CodeGen.lhs
index d7f2f70c43..7ee581a45f 100644
--- a/ghc/compiler/codeGen/CodeGen.lhs
+++ b/ghc/compiler/codeGen/CodeGen.lhs
@@ -53,7 +53,7 @@ import OccName		( mkLocalOcc )
 import TyCon            ( isDataTyCon )
 import Module		( Module, mkModuleName )
 import ErrUtils		( dumpIfSet_dyn, showPass )
-import Panic		( assertPanic, trace )
+import Panic		( assertPanic )
 import qualified Module ( moduleName )
 
 #ifdef DEBUG