diff options
| author | Vladislav Zavialov <vlad.z.4096@gmail.com> | 2020-06-19 10:46:02 +0300 |
|---|---|---|
| committer | Marge Bot <ben+marge-bot@smart-cactus.org> | 2020-07-01 15:41:38 -0400 |
| commit | cbb6b62f54c77637e29bc66e3d1214541c347753 (patch) | |
| tree | 7c6533d46ae1841d7ef6a1ade39edc72393b43e9 /compiler/GHC/Parser.y | |
| parent | 85310fb83fdb7d7294bd453026102fc42000bf14 (diff) | |
| download | haskell-cbb6b62f54c77637e29bc66e3d1214541c347753.tar.gz | |
Implement -XLexicalNegation (GHC Proposal #229)
This patch introduces a new extension, -XLexicalNegation, which detects
whether the minus sign stands for negation or subtraction using the
whitespace-based rules described in GHC Proposal #229.
Updates haddock submodule.
Diffstat (limited to 'compiler/GHC/Parser.y')
| -rw-r--r-- | compiler/GHC/Parser.y | 25 |
1 files changed, 20 insertions, 5 deletions
diff --git a/compiler/GHC/Parser.y b/compiler/GHC/Parser.y index 618fc2d393..041b25d586 100644 --- a/compiler/GHC/Parser.y +++ b/compiler/GHC/Parser.y @@ -93,7 +93,7 @@ import GHC.Builtin.Types ( unitTyCon, unitDataCon, tupleTyCon, tupleDataCon, nil manyDataConTyCon) } -%expect 232 -- shift/reduce conflicts +%expect 234 -- shift/reduce conflicts {- Last updated: 08 June 2020 @@ -553,6 +553,7 @@ are the most common patterns, rewritten as regular expressions for clarity: '-' { L _ ITminus } PREFIX_TILDE { L _ ITtilde } PREFIX_BANG { L _ ITbang } + PREFIX_MINUS { L _ ITprefixminus } '*' { L _ (ITstar _) } '-<' { L _ (ITlarrowtail _) } -- for arrow notation '>-' { L _ (ITrarrowtail _) } -- for arrow notation @@ -703,10 +704,21 @@ litpkgname_segment :: { Located FastString } | CONID { sL1 $1 $ getCONID $1 } | special_id { $1 } +-- Parse a minus sign regardless of whether -XLexicalNegation is turned on or off. +-- See Note [Minus tokens] in GHC.Parser.Lexer +HYPHEN :: { [AddAnn] } + : '-' { [mj AnnMinus $1 ] } + | PREFIX_MINUS { [mj AnnMinus $1 ] } + | VARSYM {% if (getVARSYM $1 == fsLit "-") + then return [mj AnnMinus $1] + else do { addError (getLoc $1) $ text "Expected a hyphen" + ; return [] } } + + litpkgname :: { Located FastString } : litpkgname_segment { $1 } -- a bit of a hack, means p - b is parsed same as p-b, enough for now. - | litpkgname_segment '-' litpkgname { sLL $1 $> $ appendFS (unLoc $1) (consFS '-' (unLoc $3)) } + | litpkgname_segment HYPHEN litpkgname { sLL $1 $> $ appendFS (unLoc $1) (consFS '-' (unLoc $3)) } mayberns :: { Maybe [LRenaming] } : {- empty -} { Nothing } @@ -2738,12 +2750,12 @@ prag_e :: { Located ([AddAnn], HsPragE GhcPs) } HsPragSCC noExtField (getSCC_PRAGs $1) (StringLiteral NoSourceText (getVARID $2))) } - | '{-# GENERATED' STRING INTEGER ':' INTEGER '-' INTEGER ':' INTEGER '#-}' + | '{-# GENERATED' STRING INTEGER ':' INTEGER HYPHEN INTEGER ':' INTEGER '#-}' { let getINT = fromInteger . il_value . getINTEGER in sLL $1 $> $ ([mo $1,mj AnnVal $2 ,mj AnnVal $3,mj AnnColon $4 - ,mj AnnVal $5,mj AnnMinus $6 - ,mj AnnVal $7,mj AnnColon $8 + ,mj AnnVal $5] ++ $6 ++ + [mj AnnVal $7,mj AnnColon $8 ,mj AnnVal $9,mc $10], HsPragTick noExtField (getGENERATED_PRAGs $1) @@ -2789,6 +2801,9 @@ aexp :: { ECP } | PREFIX_BANG aexp { ECP $ runECP_PV $2 >>= \ $2 -> amms (mkHsBangPatPV (comb2 $1 $>) $2) [mj AnnBang $1] } + | PREFIX_MINUS aexp { ECP $ + runECP_PV $2 >>= \ $2 -> + amms (mkHsNegAppPV (comb2 $1 $>) $2) [mj AnnMinus $1] } | '\\' apat apats '->' exp { ECP $ |