From 4229cf2d92faf5774fe1a3a9c89a5de885cf75cd Mon Sep 17 00:00:00 2001 From: Nikolay Yakimov Date: Sat, 18 Apr 2015 01:18:06 +0300 Subject: MD Reader: Smart `'` after inline math Closes #1909. Adds new parser combinator to Parsing.hs `a <+?> b` : if a succeeds, applies b and mappends output (if any) to result of a. If b fails, it's just a, if a fails, whole expression fails. --- src/Text/Pandoc/Parsing.hs | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'src/Text/Pandoc/Parsing.hs') diff --git a/src/Text/Pandoc/Parsing.hs b/src/Text/Pandoc/Parsing.hs index c18aa331f..d30c74230 100644 --- a/src/Text/Pandoc/Parsing.hs +++ b/src/Text/Pandoc/Parsing.hs @@ -161,7 +161,8 @@ module Text.Pandoc.Parsing ( anyLine, setSourceColumn, setSourceLine, newPos, - addWarning + addWarning, + (<+?>) ) where @@ -1245,3 +1246,7 @@ addWarning mbpos msg = generalize :: (Monad m) => Parser s st a -> ParserT s st m a generalize m = mkPT (\ s -> (return $ (return . runIdentity) <$> runIdentity (runParsecT m s))) + +infixr 5 <+?> +(<+?>) :: (Monoid a, Monad m) => ParserT s st m a -> ParserT s st m a -> ParserT s st m a +a <+?> b = a >>= flip fmap (try b <|> return mempty) . (<>) -- cgit v1.2.3