[project @ 2004-09-30 10:35:15 by simonpj]

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

diff --git a/ghc/compiler/typecheck/TcRnMonad.lhs b/ghc/compiler/typecheck/TcRnMonad.lhs
index e2611e3..a2db330 100644 (file)
--- a/ghc/compiler/typecheck/TcRnMonad.lhs
+++ b/ghc/compiler/typecheck/TcRnMonad.lhs
@@ -1,4 +1,4 @@
-\begin{code}
+ \begin{code}
 module TcRnMonad(
        module TcRnMonad,
        module TcRnTypes,
@@ -10,13 +10,14 @@ module TcRnMonad(
 import TcRnTypes       -- Re-export all
 import IOEnv           -- Re-export all
 
+import HsSyn           ( emptyLHsBinds )
 import HscTypes                ( HscEnv(..), ModGuts(..), ModIface(..),
-                         TyThing, Dependencies(..), TypeEnv, emptyTypeEnv,
+                         TyThing, TypeEnv, emptyTypeEnv,
                          ExternalPackageState(..), HomePackageTable,
                          ModDetails(..), HomeModInfo(..), 
                          Deprecs(..), FixityEnv, FixItem,
                          GhciMode, lookupType, unQualInScope )
-import Module          ( Module, ModuleName, unitModuleEnv, foldModuleEnv, emptyModuleEnv )
+import Module          ( Module, ModuleName, unitModuleEnv, foldModuleEnv )
 import RdrName         ( GlobalRdrEnv, emptyGlobalRdrEnv,      
                          LocalRdrEnv, emptyLocalRdrEnv )
 import Name            ( Name, isInternalName )
@@ -25,9 +26,9 @@ import NameEnv                ( extendNameEnvList )
 import InstEnv         ( InstEnv, emptyInstEnv, extendInstEnv )
 
 import VarSet          ( emptyVarSet )
-import VarEnv          ( TidyEnv, emptyTidyEnv )
+import VarEnv          ( TidyEnv, emptyTidyEnv, emptyVarEnv )
 import ErrUtils                ( Message, Messages, emptyMessages, errorsFound, 
-                         mkErrMsg, mkWarnMsg, printErrorsAndWarnings,
+                         mkWarnMsg, printErrorsAndWarnings,
                          mkLocMessage, mkLongErrMsg )
 import SrcLoc          ( mkGeneralSrcSpan, isGoodSrcSpan, SrcSpan, Located(..) )
 import NameEnv         ( emptyNameEnv )
@@ -90,7 +91,7 @@ initTc hsc_env mod do_this
                tcg_exports  = emptyNameSet,
                tcg_imports  = init_imports,
                tcg_dus      = emptyDUs,
-               tcg_binds    = emptyBag,
+               tcg_binds    = emptyLHsBinds,
                tcg_deprecs  = NoDeprecs,
                tcg_insts    = [],
                tcg_rules    = [],
@@ -106,7 +107,8 @@ initTc hsc_env mod do_this
                tcl_arrow_ctxt = topArrowCtxt,
                tcl_env        = emptyNameEnv,
                tcl_tyvars     = tvs_var,
-               tcl_lie        = panic "initTc:LIE"     -- LIE only valid inside a getLIE
+               tcl_lie        = panic "initTc:LIE",    -- LIE only valid inside a getLIE
+               tcl_gadt       = emptyVarEnv
             } ;
        } ;
    
@@ -385,26 +387,26 @@ getSrcSpanM :: TcRn SrcSpan
        -- Avoid clash with Name.getSrcLoc
 getSrcSpanM = do { env <- getLclEnv; return (tcl_loc env) }
 
-addSrcSpan :: SrcSpan -> TcRn a -> TcRn a
-addSrcSpan loc thing_inside
+setSrcSpan :: SrcSpan -> TcRn a -> TcRn a
+setSrcSpan loc thing_inside
   | isGoodSrcSpan loc = updLclEnv (\env -> env { tcl_loc = loc }) thing_inside
   | otherwise        = thing_inside    -- Don't overwrite useful info with useless
 
 addLocM :: (a -> TcM b) -> Located a -> TcM b
-addLocM fn (L loc a) = addSrcSpan loc $ fn a
+addLocM fn (L loc a) = setSrcSpan loc $ fn a
 
 wrapLocM :: (a -> TcM b) -> Located a -> TcM (Located b)
-wrapLocM fn (L loc a) = addSrcSpan loc $ do b <- fn a; return (L loc b)
+wrapLocM fn (L loc a) = setSrcSpan loc $ do b <- fn a; return (L loc b)
 
 wrapLocFstM :: (a -> TcM (b,c)) -> Located a -> TcM (Located b, c)
 wrapLocFstM fn (L loc a) =
-  addSrcSpan loc $ do
+  setSrcSpan loc $ do
     (b,c) <- fn a
     return (L loc b, c)
 
 wrapLocSndM :: (a -> TcM (b,c)) -> Located a -> TcM (b, Located c)
 wrapLocSndM fn (L loc a) =
-  addSrcSpan loc $ do
+  setSrcSpan loc $ do
     (b,c) <- fn a
     return (b, L loc c)
 \end{code}
@@ -595,25 +597,31 @@ failIfErrsM = ifErrsM failM (return ())
 %************************************************************************
 
 \begin{code}
-setErrCtxtM, addErrCtxtM :: (TidyEnv -> TcM (TidyEnv, Message)) -> TcM a -> TcM a
-setErrCtxtM msg = updCtxt (\ msgs -> [msg])
-addErrCtxtM msg = updCtxt (\ msgs -> msg : msgs)
+getErrCtxt :: TcM ErrCtxt
+getErrCtxt = do { env <- getLclEnv; return (tcl_ctxt env) }
 
-setErrCtxt, addErrCtxt :: Message -> TcM a -> TcM a
-setErrCtxt msg = setErrCtxtM (\env -> returnM (env, msg))
-addErrCtxt msg = addErrCtxtM (\env -> returnM (env, msg))
+setErrCtxt :: ErrCtxt -> TcM a -> TcM a
+setErrCtxt ctxt = updLclEnv (\ env -> env { tcl_ctxt = ctxt })
 
-popErrCtxt :: TcM a -> TcM a
-popErrCtxt = updCtxt (\ msgs -> case msgs of { [] -> []; (m:ms) -> ms })
+addErrCtxtM :: (TidyEnv -> TcM (TidyEnv, Message)) -> TcM a -> TcM a
+addErrCtxtM msg = updCtxt (\ msgs -> msg : msgs)
 
-getErrCtxt :: TcM ErrCtxt
-getErrCtxt = do { env <- getLclEnv ; return (tcl_ctxt env) }
+addErrCtxt :: Message -> TcM a -> TcM a
+addErrCtxt msg = addErrCtxtM (\env -> returnM (env, msg))
 
 -- Helper function for the above
 updCtxt :: (ErrCtxt -> ErrCtxt) -> TcM a -> TcM a
 updCtxt upd = updLclEnv (\ env@(TcLclEnv { tcl_ctxt = ctxt }) -> 
                           env { tcl_ctxt = upd ctxt })
 
+-- Conditionally add an error context
+maybeAddErrCtxt :: Maybe Message -> TcM a -> TcM a
+maybeAddErrCtxt (Just msg) thing_inside = addErrCtxt msg thing_inside
+maybeAddErrCtxt Nothing    thing_inside = thing_inside
+
+popErrCtxt :: TcM a -> TcM a
+popErrCtxt = updCtxt (\ msgs -> case msgs of { [] -> []; (m:ms) -> ms })
+
 getInstLoc :: InstOrigin -> TcM InstLoc
 getInstLoc origin
   = do { loc <- getSrcSpanM ; env <- getLclEnv ;
@@ -623,7 +631,7 @@ addInstCtxt :: InstLoc -> TcM a -> TcM a
 -- Add the SrcSpan and context from the first Inst in the list
 --     (they all have similar locations)
 addInstCtxt (InstLoc _ src_loc ctxt) thing_inside
-  = addSrcSpan src_loc (updCtxt (\ old_ctxt -> ctxt) thing_inside)
+  = setSrcSpan src_loc (updCtxt (\ old_ctxt -> ctxt) thing_inside)
 \end{code}
 
     The addErrTc functions add an error message, but do not cause failure.
@@ -693,7 +701,18 @@ ctxt_to_use ctxt | opt_PprStyle_Debug = ctxt
                 | otherwise          = take 3 ctxt
 \end{code}
 
-%************************************************************************
+debugTc is useful for monadi debugging code
+
+\begin{code}
+debugTc :: TcM () -> TcM ()
+#ifdef DEBUG
+debugTc thing = thing
+#else
+debugTc thing = return ()
+#endif
+\end{code}
+
+ %************************************************************************
 %*                                                                     *
             Type constraints (the so-called LIE)
 %*                                                                     *
@@ -914,3 +933,17 @@ forkM doc thing_inside
                        Nothing -> pprPanic "forkM" doc
                        Just r  -> r) }
 \end{code}
+
+%************************************************************************
+%*                                                                     *
+            Stuff for GADTs
+%*                                                                     *
+%************************************************************************
+
+\begin{code}
+getTypeRefinement :: TcM GadtRefinement
+getTypeRefinement = do { lcl_env <- getLclEnv; return (tcl_gadt lcl_env) }
+
+setTypeRefinement :: GadtRefinement -> TcM a -> TcM a
+setTypeRefinement gadt = updLclEnv (\env -> env { tcl_gadt = gadt })
+\end{code}