[project @ 2000-10-24 08:40:09 by simonpj]

[ghc-hetmet.git] / ghc / compiler / typecheck / TcInstDcls.lhs

diff --git a/ghc/compiler/typecheck/TcInstDcls.lhs b/ghc/compiler/typecheck/TcInstDcls.lhs
index a94d11f..571ebf7 100644 (file)
--- a/ghc/compiler/typecheck/TcInstDcls.lhs
+++ b/ghc/compiler/typecheck/TcInstDcls.lhs
@@ -11,15 +11,15 @@ module TcInstDcls ( tcInstDecls1, tcInstDecls2, tcAddDeclCtxt ) where
 
 import CmdLineOpts     ( DynFlag(..), dopt )
 
-import HsSyn           ( HsDecl(..), InstDecl(..), TyClDecl(..),
-                         MonoBinds(..), HsExpr(..),  HsLit(..), Sig(..),
+import HsSyn           ( HsDecl(..), InstDecl(..), TyClDecl(..), InPat(..),
+                         MonoBinds(..), HsExpr(..),  HsLit(..), Sig(..), Match(..),
                          andMonoBindList, collectMonoBinders, isClassDecl
                        )
 import HsTypes          ( HsType (..), HsTyVarBndr(..), toHsTyVar )
-import HsPat            ( InPat (..) )
-import HsMatches        ( Match (..) )
-import RnHsSyn         ( RenamedHsBinds, RenamedInstDecl, RenamedHsDecl,
-                         extractHsTyVars )
+import RnHsSyn         ( RenamedHsBinds, RenamedInstDecl, RenamedHsDecl, RenamedMonoBinds,
+                         RenamedTyClDecl, RenamedHsType, 
+                         extractHsTyVars, maybeGenericMatch
+                       )
 import TcHsSyn         ( TcMonoBinds, mkHsConApp )
 import TcBinds         ( tcSpecSigs )
 import TcClassDcl      ( tcMethodBind, badMethodErr )
@@ -33,7 +33,7 @@ import TcEnv          ( TcEnv, tcExtendGlobalValEnv,
                          tcAddImportedIdInfo, tcInstId, tcLookupClass,
                          newDFunName, tcExtendTyVarEnv
                        )
-import InstEnv ( InstInfo(..), InstEnv, pprInstInfo, classDataCon, 
+import InstEnv         ( InstInfo(..), InstEnv, pprInstInfo, classDataCon, 
                          simpleInstInfoTyCon, simpleInstInfoTy, isLocalInst,
                          extendInstEnv )
 import TcMonoType      ( tcTyVars, tcHsSigType, tcHsType, kcHsSigType )
@@ -56,8 +56,8 @@ import NameSet                ( emptyNameSet, nameSetToList )
 import PrelInfo                ( eRROR_ID )
 import PprType         ( pprConstraint, pprPred )
 import TyCon           ( TyCon, isSynTyCon, tyConDerivings )
-import Type            ( mkTyVarTys, splitSigmaTy, isTyVarTy,
-                         splitTyConApp_maybe, splitDictTy_maybe,
+import Type            ( mkTyVarTys, splitDFunTy, isTyVarTy,
+                         splitTyConApp_maybe, splitDictTy,
                          splitAlgTyConApp_maybe, classesToPreds, classesOfPreds,
                          unUsgTy, tyVarsOfTypes, mkClassPred, mkTyVarTy,
                          getClassTys_maybe
@@ -70,11 +70,10 @@ import Name             ( Name, NameEnv, extendNameEnv_C, emptyNameEnv,
                          plusNameEnv_C, nameEnvElts )
 import FiniteMap        ( mapFM )
 import SrcLoc           ( SrcLoc )
-import RnHsSyn          -- ( RenamedMonoBinds )
 import VarSet           ( varSetElems )
 import UniqFM           ( mapUFM )
 import Unique          ( Uniquable(..) )
-import BasicTypes      ( NewOrData(..) )
+import BasicTypes      ( NewOrData(..), Fixity )
 import ErrUtils                ( dumpIfSet_dyn )
 import ListSetOps      ( Assoc, emptyAssoc, plusAssoc_C, mapAssoc, 
                          assocElts, extendAssoc_C,
@@ -170,12 +169,13 @@ Gather up the instance declarations from their various sources
 tcInstDecls1 :: PersistentCompilerState
             -> HomeSymbolTable         -- Contains instances
             -> TcEnv                   -- Contains IdInfo for dfun ids
+            -> (Name -> Maybe Fixity)  -- for deriving Show and Read
             -> Module                  -- Module for deriving
             -> [TyCon]
             -> [RenamedHsDecl]
             -> TcM (PersistentCompilerState, InstEnv, [InstInfo], RenamedHsBinds)
 
-tcInstDecls1 pcs hst unf_env mod local_tycons decls
+tcInstDecls1 pcs hst unf_env get_fixity mod local_tycons decls
   = let
        inst_decls = [inst_decl | InstD inst_decl <- decls]
        clas_decls = [clas_decl | TyClD clas_decl <- decls, isClassDecl clas_decl]
@@ -211,7 +211,7 @@ tcInstDecls1 pcs hst unf_env mod local_tycons decls
        --     we ignore deriving decls from interfaces!
        -- This stuff computes a context for the derived instance decl, so it
        -- needs to know about all the instances possible; hecne inst_env4
-    tcDeriving (pcs_PRS pcs) mod inst_env4 local_tycons
+    tcDeriving (pcs_PRS pcs) mod inst_env4 get_fixity local_tycons
                                        `thenTc` \ (deriv_inst_info, deriv_binds) ->
     addInstInfos inst_env4 deriv_inst_info                     
                                        `thenNF_Tc` \ final_inst_env ->
@@ -246,10 +246,7 @@ tcInstDecl1 mod unf_env (InstDecl poly_ty binds uprags maybe_dfun_name src_loc)
        -- Type-check all the stuff before the "where"
     tcHsSigType poly_ty                        `thenTc` \ poly_ty' ->
     let
-       (tyvars, theta, dict_ty) = splitSigmaTy poly_ty'
-       (clas, inst_tys)         = case splitDictTy_maybe dict_ty of
-                                    Just ct -> ct
-                                    Nothing -> pprPanic "tcInstDecl1" (ppr poly_ty)
+       (tyvars, theta, clas, inst_tys) = splitDFunTy poly_ty'
     in
 
     (case maybe_dfun_name of
@@ -323,7 +320,7 @@ getGenericInstances mod class_decls
     returnTc gen_inst_info
 
 get_generics mod decl@(ClassDecl context class_name tyvar_names 
-                                fundeps class_sigs def_methods pragmas 
+                                fundeps class_sigs def_methods
                                 name_list loc)
   | null groups                
   = returnTc [] -- The comon case: 
@@ -520,7 +517,7 @@ tcInstDecl2 (InstInfo { iClass = clas, iTyVars = inst_tyvars, iTys = inst_tys,
        -- Instantiate the instance decl with tc-style type variables
     tcInstId dfun_id           `thenNF_Tc` \ (inst_tyvars', dfun_theta', dict_ty') ->
     let
-       (clas, inst_tys') = expectJust "tcInstDecl2" (splitDictTy_maybe dict_ty')
+       (clas, inst_tys') = splitDictTy dict_ty'
        origin            = InstanceDeclOrigin
 
         (class_tyvars, sc_theta, _, op_items) = classBigSig clas
@@ -776,10 +773,10 @@ tcAddDeclCtxt decl thing_inside
   where
      (name, loc, thing)
        = case decl of
-           (ClassDecl _ name _ _ _ _ _ _ loc)         -> (name, loc, "class")
-           (TySynonym name _ _ loc)                   -> (name, loc, "type synonym")
-           (TyData NewType  _ name _ _ _ _ _ loc _ _) -> (name, loc, "newtype")
-           (TyData DataType _ name _ _ _ _ _ loc _ _) -> (name, loc, "data type")
+           (ClassDecl _ name _ _ _ _ _ loc)         -> (name, loc, "class")
+           (TySynonym name _ _ loc)                 -> (name, loc, "type synonym")
+           (TyData NewType  _ name _ _ _ _ loc _ _) -> (name, loc, "newtype")
+           (TyData DataType _ name _ _ _ _ loc _ _) -> (name, loc, "data type")
 
      ctxt = hsep [ptext SLIT("In the"), text thing, 
                  ptext SLIT("declaration for"), quotes (ppr name)]