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| author | Vladislav Zavialov <vlad.z.4096@gmail.com> | 2020-05-29 13:50:02 +0300 |
|---|---|---|
| committer | Marge Bot <ben+marge-bot@smart-cactus.org> | 2020-06-01 06:41:18 -0400 |
| commit | 0fde53770cacb0d54f0583707ef7ceec78f92c41 (patch) | |
| tree | 978537c734d65232080212b9580cf7fcb2daf077 /compiler/GHC/Parser.y | |
| parent | 730fcd54467e82083d56fa87e44bbe346458c531 (diff) | |
| download | haskell-0fde53770cacb0d54f0583707ef7ceec78f92c41.tar.gz | |
Improve parser error messages for TypeApplications
With this patch, we always parse f @t as a type application,
thereby producing better error messages.
This steals two syntactic forms:
* Prefix form of the @-operator in expressions. Since the @-operator is
a divergence from the Haskell Report anyway, this is not a major loss.
* Prefix form of @-patterns. Since we are stealing loose infix form
anyway, might as well sacrifice the prefix form for the sake of much
better error messages.
Diffstat (limited to 'compiler/GHC/Parser.y')
| -rw-r--r-- | compiler/GHC/Parser.y | 8 |
1 files changed, 3 insertions, 5 deletions
diff --git a/compiler/GHC/Parser.y b/compiler/GHC/Parser.y index 6dde13f7a9..a9bb4fa87d 100644 --- a/compiler/GHC/Parser.y +++ b/compiler/GHC/Parser.y @@ -2738,11 +2738,9 @@ fexp :: { ECP } mkHsAppPV (comb2 $1 $>) $1 $2 } -- See Note [Whitespace-sensitive operator parsing] in GHC.Parser.Lexer - | fexp PREFIX_AT atype {% runECP_P $1 >>= \ $1 -> - runPV (checkExpBlockArguments $1) >>= \_ -> - fmap ecpFromExp $ - ams (sLL $1 $> $ HsAppType noExtField $1 (mkHsWildCardBndrs $3)) - [mj AnnAt $2] } + | fexp PREFIX_AT atype { ECP $ + runECP_PV $1 >>= \ $1 -> + amms (mkHsAppTypePV (comb2 $1 $>) $1 $3) [mj AnnAt $2] } | 'static' aexp {% runECP_P $2 >>= \ $2 -> fmap ecpFromExp $ |