Markdown reader: Simplified and sped up str parser.

We no longer needed the smart quote complexity, because of
improvements to singleQuoteStart and singleQuoteEnd.

And we were able to move the check for intraword underscore
to the emphasis parser.

1 files changed, 9 insertions, 15 deletions

diff --git a/src/Text/Pandoc/Readers/Markdown.hs b/src/Text/Pandoc/Readers/Markdown.hs
index 75d1de67a..44cbbc676 100644
--- a/src/Text/Pandoc/Readers/Markdown.hs
+++ b/src/Text/Pandoc/Readers/Markdown.hs
@@ -1381,8 +1381,14 @@ emph = fmap B.emph <$> nested
   (inlinesBetween starStart starEnd <|> inlinesBetween ulStart ulEnd)
     where starStart = char '*' >> lookAhead nonspaceChar
           starEnd   = notFollowedBy' (() <$ strong) >> char '*'
-          ulStart   = char '_' >> lookAhead nonspaceChar
+          ulStart   = checkIntraword >> char '_' >> lookAhead nonspaceChar
           ulEnd     = notFollowedBy' (() <$ strong) >> char '_'
+          checkIntraword = do
+            exts <- getOption readerExtensions
+            when (Ext_intraword_underscores `Set.member` exts) $ do
+              pos <- getPosition
+              lastStrPos <- stateLastStrPos <$> getState
+              guard $ lastStrPos /= Just pos
 
 strong :: MarkdownParser (F Inlines)
 strong = fmap B.strong <$> nested
@@ -1421,23 +1427,11 @@ nonEndline = satisfy (/='\n')
 
 str :: MarkdownParser (F Inlines)
 str = do
-  isSmart <- getOption readerSmart
-  intrawordUnderscores <- option False $
-                          True <$ guardEnabled Ext_intraword_underscores
-  a <- alphaNum
-  as <- many $ alphaNum
-            <|> (if intrawordUnderscores
-                    then try (char '_' >>~ lookAhead alphaNum)
-                    else mzero)
-            <|> if isSmart
-                   then (try $ satisfy (\c -> c == '\'' || c == '\x2019') >>
-                         lookAhead alphaNum >> return '\x2019')
-                         -- for things like l'aide
-                   else mzero
+  result <- many1 alphaNum
   pos <- getPosition
   updateState $ \s -> s{ stateLastStrPos = Just pos }
-  let result = a:as
   let spacesToNbr = map (\c -> if c == ' ' then '\160' else c)
+  isSmart <- getOption readerSmart
   if isSmart
      then case likelyAbbrev result of
                []        -> return $ return $ B.str result