add -XNewQualifiedOperators (Haskell' qualified operator syntax)

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

diff --git a/compiler/parser/Parser.y.pp b/compiler/parser/Parser.y.pp
index 86ce98c..2f1166d 100644 (file)
--- a/compiler/parser/Parser.y.pp
+++ b/compiler/parser/Parser.y.pp
@@ -314,6 +314,8 @@ incorrect.
  QCONID        { L _ (ITqconid   _) }
  QVARSYM       { L _ (ITqvarsym  _) }
  QCONSYM       { L _ (ITqconsym  _) }
+ PREFIXQVARSYM  { L _ (ITprefixqvarsym  _) }
+ PREFIXQCONSYM  { L _ (ITprefixqconsym  _) }
 
  IPDUPVARID    { L _ (ITdupipvarid   _) }              -- GHC extension
 
@@ -495,13 +497,17 @@ importdecls :: { [LImportDecl RdrName] }
        | {- empty -}                           { [] }
 
 importdecl :: { LImportDecl RdrName }
-       : 'import' maybe_src optqualified modid maybeas maybeimpspec 
-               { L (comb4 $1 $4 $5 $6) (ImportDecl $4 $2 $3 (unLoc $5) (unLoc $6)) }
+       : 'import' maybe_src optqualified maybe_pkg modid maybeas maybeimpspec 
+               { L (comb4 $1 $5 $6 $7) (ImportDecl $5 $4 $2 $3 (unLoc $6) (unLoc $7)) }
 
 maybe_src :: { IsBootInterface }
        : '{-# SOURCE' '#-}'                    { True }
        | {- empty -}                           { False }
 
+maybe_pkg :: { Maybe FastString }
+        : STRING                                { Just (getSTRING $1) }
+        | {- empty -}                           { Nothing }
+
 optqualified :: { Bool }
        : 'qualified'                           { True  }
        | {- empty -}                           { False }
@@ -1429,16 +1435,27 @@ cvtopdecls0 :: { [LHsDecl RdrName] }
        : {- empty -}           { [] }
        | cvtopdecls            { $1 }
 
--- tuple expressions: things that can appear unparenthesized as long as they're
+-- "texp" is short for tuple expressions: 
+-- things that can appear unparenthesized as long as they're
 -- inside parens or delimitted by commas
 texp :: { LHsExpr RdrName }
        : exp                           { $1 }
-       -- Technically, this should only be used for bang patterns,
-       -- but we can be a little more liberal here and avoid parens
-       -- inside tuples
-       | infixexp qop  { LL $ SectionL $1 $2 }
+
+       -- Note [Parsing sections]
+       -- ~~~~~~~~~~~~~~~~~~~~~~~
+       -- We include left and right sections here, which isn't
+       -- technically right according to Haskell 98.  For example
+       --      (3 +, True) isn't legal
+       -- However, we want to parse bang patterns like
+       --      (!x, !y)
+       -- and it's convenient to do so here as a section
+        -- Then when converting expr to pattern we unravel it again
+       -- Meanwhile, the renamer checks that real sections appear
+       -- inside parens.
+        | infixexp qop         { LL $ SectionL $1 $2 }
        | qopm infixexp       { LL $ SectionR $1 $2 }
-       -- view patterns get parenthesized above
+
+       -- View patterns get parenthesized above
        | exp '->' exp   { LL $ EViewPat $1 $3 }
 
 texps :: { [LHsExpr RdrName] }
@@ -1724,6 +1741,7 @@ qtyconop :: { Located RdrName }   -- Qualified or unqualified
 
 qtycon :: { Located RdrName }  -- Qualified or unqualified
        : QCONID                        { L1 $! mkQual tcClsName (getQCONID $1) }
+        | PREFIXQCONSYM                 { L1 $! mkQual tcClsName (getPREFIXQCONSYM $1) }
        | tycon                         { $1 }
 
 tycon  :: { Located RdrName }  -- Unqualified
@@ -1804,17 +1822,15 @@ qvar    :: { Located RdrName }
 
 qvarid :: { Located RdrName }
        : varid                 { $1 }
-       | QVARID                { L1 $ mkQual varName (getQVARID $1) }
+       | QVARID                { L1 $! mkQual varName (getQVARID $1) }
+        | PREFIXQVARSYM         { L1 $! mkQual varName (getPREFIXQVARSYM $1) }
 
 varid :: { Located RdrName }
-       : varid_no_unsafe       { $1 }
+       : VARID                 { L1 $! mkUnqual varName (getVARID $1) }
+       | special_id            { L1 $! mkUnqual varName (unLoc $1) }
        | 'unsafe'              { L1 $! mkUnqual varName (fsLit "unsafe") }
        | 'safe'                { L1 $! mkUnqual varName (fsLit "safe") }
        | 'threadsafe'          { L1 $! mkUnqual varName (fsLit "threadsafe") }
-
-varid_no_unsafe :: { Located RdrName }
-       : VARID                 { L1 $! mkUnqual varName (getVARID $1) }
-       | special_id            { L1 $! mkUnqual varName (unLoc $1) }
        | 'forall'              { L1 $! mkUnqual varName (fsLit "forall") }
        | 'family'              { L1 $! mkUnqual varName (fsLit "family") }
 
@@ -1863,7 +1879,8 @@ special_sym : '!' { L1 (fsLit "!") }
 
 qconid :: { Located RdrName }  -- Qualified or unqualified
        : conid                 { $1 }
-       | QCONID                { L1 $ mkQual dataName (getQCONID $1) }
+       | QCONID                { L1 $! mkQual dataName (getQCONID $1) }
+        | PREFIXQCONSYM         { L1 $! mkQual dataName (getPREFIXQCONSYM $1) }
 
 conid  :: { Located RdrName }
        : CONID                 { L1 $ mkUnqual dataName (getCONID $1) }
@@ -1972,6 +1989,8 @@ getQVARID         (L _ (ITqvarid   x)) = x
 getQCONID      (L _ (ITqconid   x)) = x
 getQVARSYM     (L _ (ITqvarsym  x)) = x
 getQCONSYM     (L _ (ITqconsym  x)) = x
+getPREFIXQVARSYM (L _ (ITprefixqvarsym  x)) = x
+getPREFIXQCONSYM (L _ (ITprefixqconsym  x)) = x
 getIPDUPVARID   (L _ (ITdupipvarid   x)) = x
 getCHAR                (L _ (ITchar     x)) = x
 getSTRING      (L _ (ITstring   x)) = x