remove empty dir

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

diff --git a/ghc/compiler/types/Class.lhs b/ghc/compiler/types/Class.lhs
index 78661b1..016ce1b 100644 (file)
--- a/ghc/compiler/types/Class.lhs
+++ b/ghc/compiler/types/Class.lhs
@@ -5,24 +5,24 @@
 
 \begin{code}
 module Class (
-       Class, ClassOpItem,
+       Class, ClassOpItem, FunDep,
+       DefMeth (..),
 
-       mkClass, classTyVars,
-       classKey, classSelIds, classTyCon,
-       classBigSig, classInstEnv
+       mkClass, classTyVars, classArity,
+       classKey, className, classSelIds, classTyCon, classMethods,
+       classBigSig, classExtraBigSig, classTvsFds, classSCTheta
     ) 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
 \end{code}
 
 %************************************************************************
@@ -39,45 +39,51 @@ 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)
+       -- Selector function; contains unfolding
+       -- Default-method info
+
+data DefMeth = NoDefMeth               -- No default method
+            | DefMeth                  -- A polymorphic default method
+            | 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 +96,28 @@ mkClass name tyvars super_classes superdict_sels
 The rest of these functions are just simple selectors.
 
 \begin{code}
-classSelIds (Class {classSCSels = sc_sels, classOpStuff = op_stuff})
-  = sc_sels ++ [op_sel | (op_sel, _, _) <- op_stuff]
+classArity :: Class -> Arity
+classArity clas = length (classTyVars clas)
+       -- Could memoise this
+
+classSelIds :: Class -> [Id]
+classSelIds c@(Class {classSCSels = sc_sels})
+  = sc_sels ++ classMethods c
+
+classMethods :: Class -> [Id]
+classMethods (Class {classOpStuff = op_stuff})
+  = [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)
 \end{code}
 
 
@@ -132,6 +154,11 @@ instance Outputable Class where
 
 instance Show Class where
     showsPrec p c = showsPrecSDoc p (ppr c)
+
+instance Outputable DefMeth where
+    ppr DefMeth     =  text "{- has default method -}"
+    ppr GenDefMeth  =  text "{- has generic method -}"
+    ppr NoDefMeth   =  empty   -- No default method
 \end{code}