[project @ 1999-06-28 15:42:33 by simonmar]

[ghc-hetmet.git] / ghc / compiler / parser / ParseUtil.lhs

diff --git a/ghc/compiler/parser/ParseUtil.lhs b/ghc/compiler/parser/ParseUtil.lhs
index ce4f71b..2be5030 100644 (file)
--- a/ghc/compiler/parser/ParseUtil.lhs
+++ b/ghc/compiler/parser/ParseUtil.lhs
@@ -14,6 +14,10 @@ module ParseUtil (
        , mkRecConstrOrUpdate   -- HsExp -> [HsFieldUpdate] -> P HsExp
        , groupBindings
 
+       , checkAs
+       , checkHiding
+       , checkQualified
+
        , checkPrec             -- String -> P String
        , checkCallConv         -- FAST_STRING -> P CallConv
        , checkContext          -- HsType -> P HsContext
@@ -33,10 +37,9 @@ module ParseUtil (
        , funTyCon_RDR
 
        -- pseudo-keywords, in var and tyvar forms (all :: RdrName)
-       , as_var_RDR, hiding_var_RDR, qualified_var_RDR, forall_var_RDR
+       , forall_var_RDR
        , export_var_RDR, label_var_RDR, dynamic_var_RDR, unsafe_var_RDR
 
-       , as_tyvar_RDR, hiding_tyvar_RDR, qualified_tyvar_RDR
        , export_tyvar_RDR, label_tyvar_RDR, dynamic_tyvar_RDR
        , unsafe_tyvar_RDR
 
@@ -69,6 +72,9 @@ parseError s =
   getSrcLocP `thenP` \ loc ->
   failMsgP (hcat [ppr loc, text ": ", text s])
 
+parseErrorOnInput :: P a
+parseErrorOnInput buf PState{ loc = loc } = PFailed (srcParseErr buf loc)
+
 srcParseErr :: StringBuffer -> SrcLoc -> Message
 srcParseErr s l
   = hcat [ppr l, ptext SLIT(": parse error on input "),
@@ -77,6 +83,18 @@ srcParseErr s l
 cbot = panic "CCall:result_ty"
 
 -----------------------------------------------------------------------------
+-- Special Ids
+
+checkAs, checkQualified, checkHiding :: FAST_STRING -> P ()
+
+checkAs s       | s == SLIT("as")        = returnP ()
+                | otherwise              = parseErrorOnInput
+checkQualified s | s == SLIT("qualified") = returnP ()
+                | otherwise              = parseErrorOnInput
+checkHiding s           | s == SLIT("hiding")    = returnP ()
+                | otherwise              = parseErrorOnInput
+
+-----------------------------------------------------------------------------
 -- splitForConApp
 
 -- When parsing data declarations, we sometimes inadvertently parse
@@ -428,27 +446,18 @@ unitName = SLIT("()")
 funName  = SLIT("(->)")
 listName = SLIT("[]")
 
-asName              = SLIT("as")
-hidingName          = SLIT("hiding")
-qualifiedName       = SLIT("qualified")
 forallName          = SLIT("forall")
 exportName         = SLIT("export")
 labelName          = SLIT("label")
 dynamicName        = SLIT("dynamic")
 unsafeName          = SLIT("unsafe")
 
-as_var_RDR          = mkSrcUnqual varName asName
-hiding_var_RDR      = mkSrcUnqual varName hidingName
-qualified_var_RDR   = mkSrcUnqual varName qualifiedName
 forall_var_RDR      = mkSrcUnqual varName forallName
 export_var_RDR      = mkSrcUnqual varName exportName
 label_var_RDR       = mkSrcUnqual varName labelName
 dynamic_var_RDR     = mkSrcUnqual varName dynamicName
 unsafe_var_RDR      = mkSrcUnqual varName unsafeName
 
-as_tyvar_RDR        = mkSrcUnqual tvName asName
-hiding_tyvar_RDR    = mkSrcUnqual tvName hidingName
-qualified_tyvar_RDR = mkSrcUnqual tvName qualifiedName
 export_tyvar_RDR    = mkSrcUnqual tvName exportName
 label_tyvar_RDR     = mkSrcUnqual tvName labelName
 dynamic_tyvar_RDR   = mkSrcUnqual tvName dynamicName