[project @ 2005-02-23 13:46:43 by simonpj]

[ghc-hetmet.git] / ghc / compiler / parser / Parser.y.pp

diff --git a/ghc/compiler/parser/Parser.y.pp b/ghc/compiler/parser/Parser.y.pp
index 01ad579..d143540 100644 (file)
--- a/ghc/compiler/parser/Parser.y.pp
+++ b/ghc/compiler/parser/Parser.y.pp
@@ -16,7 +16,7 @@ INCLUDE "HsVersions.h"
 
 import HsSyn
 import RdrHsSyn
-import HscTypes                ( ModIface, IsBootInterface, DeprecTxt )
+import HscTypes                ( IsBootInterface, DeprecTxt )
 import Lexer
 import RdrName
 import TysWiredIn      ( unitTyCon, unitDataCon, tupleTyCon, tupleCon, nilDataCon,
@@ -36,7 +36,6 @@ import Type           ( Kind, mkArrowKind, liftedTypeKind )
 import BasicTypes      ( Boxity(..), Fixity(..), FixityDirection(..), IPName(..),
                          Activation(..) )
 import OrdList
-import Bag             ( emptyBag )
 import Panic
 
 import FastString
@@ -437,15 +436,20 @@ topdecl :: { OrdList (LHsDecl RdrName) }
        | decl                                  { unLoc $1 }
 
 tycl_decl :: { LTyClDecl RdrName }
-       : 'type' syn_hdr '=' ctype      
-               -- Note ctype, not sigtype.
+       : 'type' type '=' ctype 
+               -- Note type on the left of the '='; this allows
+               -- infix type constructors to be declared
+               -- 
+               -- Note ctype, not sigtype, on the right
                -- We allow an explicit for-all but we don't insert one
                -- in   type Foo a = (b,b)
                -- Instead we just say b is out of scope
-               { LL $ let (tc,tvs) = $2 in TySynonym tc tvs $4 }
+               {% do { (tc,tvs) <- checkSynHdr $2
+                     ; return (LL (TySynonym tc tvs $4)) } }
 
        | 'data' tycl_hdr constrs deriving
-               { L (comb4 $1 $2 $3 $4)
+               { L (comb4 $1 $2 $3 $4) -- We need the location on tycl_hdr 
+                                       -- in case constrs and deriving are both empty
                    (mkTyData DataType $2 Nothing (reverse (unLoc $3)) (unLoc $4)) }
 
         | 'data' tycl_hdr opt_kind_sig 'where' gadt_constrlist -- No deriving for GADTs
@@ -467,12 +471,6 @@ opt_kind_sig :: { Maybe Kind }
        :                               { Nothing }
        | '::' kind                     { Just $2 }
 
-syn_hdr :: { (Located RdrName, [LHsTyVarBndr RdrName]) }
-               -- We don't retain the syntax of an infix
-               -- type synonym declaration. Oh well.
-       : tycon tv_bndrs                { ($1, $2) }
-       | tv_bndr tyconop tv_bndr       { ($2, [$1,$3]) }
-
 -- tycl_hdr parses the header of a type or class decl,
 -- which takes the form
 --     T a b
@@ -480,7 +478,7 @@ syn_hdr :: { (Located RdrName, [LHsTyVarBndr RdrName]) }
 --     (Eq a, Ord b) => T a b
 -- Rather a lot of inlining here, else we get reduce/reduce errors
 tycl_hdr :: { Located (LHsContext RdrName, Located RdrName, [LHsTyVarBndr RdrName]) }
-       : context '=>' type             {% checkTyClHdr $1 $3 >>= return.LL }
+       : context '=>' type             {% checkTyClHdr $1         $3 >>= return.LL }
        | type                          {% checkTyClHdr (noLoc []) $1 >>= return.L1 }
 
 -----------------------------------------------------------------------------