diff options
Diffstat (limited to 'compiler/parser/Parser.y')
| -rw-r--r-- | compiler/parser/Parser.y | 27 |
1 files changed, 24 insertions, 3 deletions
diff --git a/compiler/parser/Parser.y b/compiler/parser/Parser.y index 74db997bbb..d7aef8d77f 100644 --- a/compiler/parser/Parser.y +++ b/compiler/parser/Parser.y @@ -29,7 +29,7 @@ module Parser (parseModule, parseSignature, parseImport, parseStatement, parseBa parseType, parseHeader) where -- base -import Control.Monad ( unless, liftM ) +import Control.Monad ( unless, liftM, when ) import GHC.Exts import Data.Char import Control.Monad ( mplus ) @@ -2483,8 +2483,14 @@ infixexp :: { LHsExpr GhcPs } infixexp_top :: { LHsExpr GhcPs } : exp10_top { $1 } | infixexp_top qop exp10_top - {% ams (sLL $1 $> (OpApp noExt $1 $2 $3)) - [mj AnnVal $2] } + {% do { when (srcSpanEnd (getLoc $2) + == srcSpanStart (getLoc $3) + && checkIfBang $2) $ + warnSpaceAfterBang (comb2 $2 $3); + ams (sLL $1 $> (OpApp noExt $1 $2 $3)) + [mj AnnVal $2] + } + } exp10_top :: { LHsExpr GhcPs } @@ -3705,6 +3711,21 @@ hintExplicitForall' span = do , text "extension to enable explicit-forall syntax: forall <tvs>. <type>" ] +checkIfBang :: LHsExpr GhcPs -> Bool +checkIfBang (L _ (HsVar _ (L _ op))) = op == bang_RDR +checkIfBang _ = False + +-- | Warn about missing space after bang +warnSpaceAfterBang :: SrcSpan -> P () +warnSpaceAfterBang span = do + bang_on <- extension bangPatEnabled + unless bang_on $ + addWarning Opt_WarnSpaceAfterBang span msg + where + msg = text "Did you forget to enable BangPatterns?" $$ + text "If you mean to bind (!) then perhaps you want" $$ + text "to add a space after the bang for clarity." + -- When two single quotes don't followed by tyvar or gtycon, we report the -- error as empty character literal, or TH quote that missing proper type -- variable or constructor. See Trac #13450. |