X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Ftypes%2FClass.lhs;h=6aced85121c23a50381446c6f4dd1ddf5617f57c;hb=d254a44b8392ff0a4327f1916ef921887ce78769;hp=78661b13210e0dc4e2e76c984c3dd9e7209f3eb2;hpb=e1a4f2a5be6e4cd06d96b601fefd519c2569ba99;p=ghc-hetmet.git

diff --git a/ghc/compiler/types/Class.lhs b/ghc/compiler/types/Class.lhs
index 78661b1..6aced85 100644
--- a/ghc/compiler/types/Class.lhs
+++ b/ghc/compiler/types/Class.lhs
@@ -5,24 +5,26 @@
 
 \begin{code}
 module Class (
-	Class, ClassOpItem,
+	Class, ClassOpItem, FunDep,
+	DefMeth (..),
 
-	mkClass, classTyVars,
-	classKey, classSelIds, classTyCon,
-	classBigSig, classInstEnv
+	mkClass, classTyVars, classArity,
+	classKey, className, classSelIds, classTyCon,
+	classBigSig, classExtraBigSig, classTvsFds, classSCTheta,
+ 	classHasFDs
     ) where
 
 #include "HsVersions.h"
 
 import {-# SOURCE #-} TyCon	( TyCon )
-import {-# SOURCE #-} TypeRep	( Type )
-import {-# SOURCE #-} InstEnv	( InstEnv )
+import {-# SOURCE #-} TypeRep	( PredType )
 
 import Var		( Id, TyVar )
 import Name		( NamedThing(..), Name )
+import BasicTypes	( Arity )
 import Unique		( Unique, Uniquable(..) )
 import Outputable
-import Util
+import Util             ( notNull )
 \end{code}
 
 %************************************************************************
@@ -39,45 +41,51 @@ data Class
 	classKey  :: Unique,			-- Key for fast comparison
 	className :: Name,
 	
-	classTyVars :: [TyVar],			-- The class type variables
+	classTyVars  :: [TyVar],		-- The class type variables
+	classFunDeps :: [FunDep TyVar],		-- The functional dependencies
 
-	classSCTheta :: [(Class,[Type])],	-- Immediate superclasses, and the
+	classSCTheta :: [PredType],		-- Immediate superclasses, and the
 	classSCSels  :: [Id],			-- corresponding selector functions to
 						-- extract them from a dictionary of this
 						-- class
 
 	classOpStuff :: [ClassOpItem],		-- Ordered by tag
 
-	classInstEnv :: InstEnv,	-- All the instances of this class
-
 	classTyCon :: TyCon		-- The data type constructor for dictionaries
   }					-- of this class
 
-type ClassOpItem = (Id, 	--   Selector function; contains unfolding
-		    Id, 	--   Default methods
-		    Bool)	--   True <=> an explicit default method was 
-				--	      supplied in the class decl
+type FunDep a	  = ([a],[a])	--  e.g. class C a b c |  a b -> c, a c -> b  where ...
+				--  Here fun-deps are [([a,b],[c]), ([a,c],[b])]
+
+type ClassOpItem = (Id, DefMeth Name)
+	-- Selector function; contains unfolding
+	-- Default-method info
+
+data DefMeth id = NoDefMeth 		-- No default method
+	        | DefMeth id 		-- A polymorphic default method (named id)
+	        | GenDefMeth 		-- A generic default method
+                deriving Eq  
 \end{code}
 
 The @mkClass@ function fills in the indirect superclasses.
 
 \begin{code}
 mkClass :: Name -> [TyVar]
-	-> [(Class,[Type])] -> [Id]
-	-> [(Id, Id, Bool)]
+	-> [([TyVar], [TyVar])]
+	-> [PredType] -> [Id]
+	-> [ClassOpItem]
 	-> TyCon
-	-> InstEnv
 	-> Class
 
-mkClass name tyvars super_classes superdict_sels
-	op_stuff tycon class_insts
+mkClass name tyvars fds super_classes superdict_sels
+	op_stuff tycon
   = Class {	classKey = getUnique name, 
 		className = name,
 		classTyVars = tyvars,
+		classFunDeps = fds,
 		classSCTheta = super_classes,
 		classSCSels = superdict_sels,
 		classOpStuff = op_stuff,
-		classInstEnv = class_insts,
 		classTyCon = tycon }
 \end{code}
 
@@ -90,12 +98,26 @@ mkClass name tyvars super_classes superdict_sels
 The rest of these functions are just simple selectors.
 
 \begin{code}
+classArity :: Class -> Arity
+classArity clas = length (classTyVars clas)
+	-- Could memoise this
+
 classSelIds (Class {classSCSels = sc_sels, classOpStuff = op_stuff})
-  = sc_sels ++ [op_sel | (op_sel, _, _) <- op_stuff]
+  = sc_sels ++ [op_sel | (op_sel, _) <- op_stuff]
+
+classTvsFds c
+  = (classTyVars c, classFunDeps c)
 
 classBigSig (Class {classTyVars = tyvars, classSCTheta = sc_theta, 
 	 	    classSCSels = sc_sels, classOpStuff = op_stuff})
   = (tyvars, sc_theta, sc_sels, op_stuff)
+classExtraBigSig (Class {classTyVars = tyvars, classFunDeps = fundeps,
+			 classSCTheta = sc_theta, classSCSels = sc_sels,
+			 classOpStuff = op_stuff})
+  = (tyvars, fundeps, sc_theta, sc_sels, op_stuff)
+
+classHasFDs :: Class -> Bool
+classHasFDs (Class {classFunDeps = fundeps}) = notNull fundeps
 \end{code}