[project @ 2003-07-21 15:14:18 by ross]

[ghc-hetmet.git] / ghc / compiler / types / Class.lhs

diff --git a/ghc/compiler/types/Class.lhs b/ghc/compiler/types/Class.lhs
index 274c25c..3a37d16 100644 (file)
--- a/ghc/compiler/types/Class.lhs
+++ b/ghc/compiler/types/Class.lhs
@@ -5,24 +5,26 @@
 
 \begin{code}
 module Class (
-       Class, ClassOpItem, ClassPred, ClassContext, FunDep,
+       Class, ClassOpItem, FunDep,
        DefMeth (..),
 
        mkClass, classTyVars, classArity,
        classKey, className, classSelIds, classTyCon,
-       classBigSig, classExtraBigSig, classTvsFds, classSCTheta
+       classBigSig, classExtraBigSig, classTvsFds, classSCTheta,
+       classHasFDs
     ) where
 
 #include "HsVersions.h"
 
 import {-# SOURCE #-} TyCon    ( TyCon )
-import {-# SOURCE #-} TypeRep  ( Type )
+import {-# SOURCE #-} TypeRep  ( PredType )
 
 import Var             ( Id, TyVar )
 import Name            ( NamedThing(..), Name )
 import BasicTypes      ( Arity )
 import Unique          ( Unique, Uniquable(..) )
 import Outputable
+import Util             ( notNull )
 \end{code}
 
 %************************************************************************
@@ -42,7 +44,7 @@ data Class
        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
@@ -52,18 +54,16 @@ data Class
        classTyCon :: TyCon             -- The data type constructor for dictionaries
   }                                    -- of this class
 
-type ClassPred           = (Class, [Type])
-type ClassContext = [ClassPred]
-
 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 Id)
+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)
+                                       --      (Only instantiated to RdrName and Name, never Id)
                | GenDefMeth            -- A generic default method
                 deriving Eq  
 \end{code}
@@ -73,7 +73,7 @@ The @mkClass@ function fills in the indirect superclasses.
 \begin{code}
 mkClass :: Name -> [TyVar]
        -> [([TyVar], [TyVar])]
-       -> [(Class,[Type])] -> [Id]
+       -> [PredType] -> [Id]
        -> [ClassOpItem]
        -> TyCon
        -> Class
@@ -116,6 +116,9 @@ 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}