{-
-----------------------------------------------------------------------------
-$Id: Parser.y,v 1.5 1999/06/03 14:44:23 simonmar Exp $
+$Id: Parser.y,v 1.6 1999/06/07 14:58:40 simonmar Exp $
Haskell grammar.
: ctype {% checkInstType $1 }
ctype :: { RdrNameHsType }
- : 'forall' tyvars '.' btype '=>' type
- {% checkContext $4 `thenP` \c ->
- returnP (HsForAllTy (Just $2) c $6) }
+ : 'forall' tyvars '.' context type
+ { HsForAllTy (Just $2) $4 $5 }
| 'forall' tyvars '.' type { HsForAllTy (Just $2) [] $4 }
- | btype '=>' type {% checkContext $1 `thenP` \c ->
- returnP (HsForAllTy Nothing c $3) }
+ | context type { HsForAllTy Nothing $1 $2 }
| type { $1 }
types0 :: { [RdrNameHsType] }
: constrs '|' constr { $3 : $1 }
| constr { [$1] }
-{- ToDo: existential stuff -}
-
constr :: { RdrNameConDecl }
- : srcloc scontype
- { ConDecl (fst $2) [] [] (VanillaCon (snd $2)) $1 }
- | srcloc sbtype conop sbtype
- { ConDecl $3 [] [] (InfixCon $2 $4) $1 }
- | srcloc con '{' fielddecls '}'
- { ConDecl $2 [] [] (RecCon (reverse $4)) $1 }
+ : srcloc forall context constr_stuff
+ { ConDecl (fst $4) $2 $3 (snd $4) $1 }
+ | srcloc forall constr_stuff
+ { ConDecl (fst $3) $2 [] (snd $3) $1 }
+
+forall :: { [RdrNameHsTyVar] }
+ : 'forall' tyvars '.' { $2 }
+ | {- empty -} { [] }
+
+context :: { RdrNameContext }
+ : btype '=>' {% checkContext $1 }
+
+constr_stuff :: { (RdrName, RdrNameConDetails) }
+ : scontype { (fst $1, VanillaCon (snd $1)) }
+ | sbtype conop sbtype { ($2, InfixCon $1 $3) }
+ | con '{' fielddecls '}' { ($1, RecCon (reverse $3)) }
newconstr :: { RdrNameConDecl }
: srcloc conid atype { ConDecl $2 [] [] (NewCon $3 Nothing) $1 }