[project @ 2001-01-25 17:54:24 by simonpj]

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

diff --git a/ghc/compiler/typecheck/TcMonad.lhs b/ghc/compiler/typecheck/TcMonad.lhs
index b13a511..3e3322e 100644 (file)
--- a/ghc/compiler/typecheck/TcMonad.lhs
+++ b/ghc/compiler/typecheck/TcMonad.lhs
@@ -2,7 +2,7 @@
 module TcMonad(
        TcType, 
        TcTauType, TcPredType, TcThetaType, TcRhoType,
-       TcTyVar, TcTyVarSet,
+       TcTyVar, TcTyVarSet, TcClassContext,
        TcKind,
 
        TcM, NF_TcM, TcDown, TcEnv, 
@@ -54,7 +54,7 @@ import ErrUtils               ( addShortErrLocLine, addShortWarnLocLine, ErrMsg, Message, War
 
 import Bag             ( Bag, emptyBag, isEmptyBag,
                          foldBag, unitBag, unionBags, snocBag )
-import Class           ( Class )
+import Class           ( Class, ClassContext )
 import Name            ( Name )
 import Var             ( Id, TyVar, newMutTyVar, newSigTyVar, readMutTyVar, writeMutTyVar )
 import VarEnv          ( TidyEnv, emptyTidyEnv )
@@ -93,11 +93,12 @@ type TcType = Type          -- A TcType can have mutable type variables
        -- a cannot occur inside a MutTyVar in T; that is,
        -- T is "flattened" before quantifying over a
 
-type TcPredType  = PredType
-type TcThetaType = ThetaType
-type TcRhoType   = RhoType
-type TcTauType   = TauType
-type TcKind      = TcType
+type TcClassContext = ClassContext
+type TcPredType     = PredType
+type TcThetaType    = ThetaType
+type TcRhoType      = RhoType
+type TcTauType      = TauType
+type TcKind         = TcType
 \end{code}
 
 
@@ -658,6 +659,9 @@ type InstLoc = (InstOrigin, SrcLoc, ErrCtxt)
 data InstOrigin
   = OccurrenceOf Id            -- Occurrence of an overloaded identifier
 
+  | IPOcc Name                 -- Occurrence of an implicit parameter
+  | IPBind Name                        -- Binding site of an implicit parameter
+
   | RecordUpdOrigin
 
   | DataDeclOrigin             -- Typechecking a data declaration
@@ -709,6 +713,10 @@ pprInstLoc (orig, locn, ctxt)
   where
     pp_orig (OccurrenceOf id)
        = hsep [ptext SLIT("use of"), quotes (ppr id)]
+    pp_orig (IPOcc name)
+       = hsep [ptext SLIT("use of implicit parameter"), quotes (char '?' <> ppr name)]
+    pp_orig (IPBind name)
+       = hsep [ptext SLIT("binding for implicit parameter"), quotes (char '?' <> ppr name)]
     pp_orig (LiteralOrigin lit)
        = hsep [ptext SLIT("the literal"), quotes (ppr lit)]
     pp_orig (PatOrigin pat)