Introduce class HasLastStrPosition, generalize functions

Both `ParserState` and `OrgParserState` keep track of the parser position at
which the last string ended.  This patch introduces a new class
`HasLastStrPosition` and makes the above types instances of that class.  This
enables the generalization of functions updating the state or checking if one
is right after a string.

2 files changed, 7 insertions, 15 deletions

diff --git a/src/Text/Pandoc/Readers/Markdown.hs b/src/Text/Pandoc/Readers/Markdown.hs
index d1637b701..1ac98e94c 100644
--- a/src/Text/Pandoc/Readers/Markdown.hs
+++ b/src/Text/Pandoc/Readers/Markdown.hs
@@ -1474,9 +1474,7 @@ strongOrEmph =  enclosure '*' <|> (checkIntraword >> enclosure '_')
   where  checkIntraword = do
            exts <- getOption readerExtensions
            when (Ext_intraword_underscores `Set.member` exts) $ do
-             pos <- getPosition
-             lastStrPos <- stateLastStrPos <$> getState
-             guard $ lastStrPos /= Just pos
+             guard =<< notAfterString
 
 -- | Parses a list of inlines between start and end delimiters.
 inlinesBetween :: (Show b)
@@ -1518,8 +1516,7 @@ nonEndline = satisfy (/='\n')
 str :: MarkdownParser (F Inlines)
 str = do
   result <- many1 alphaNum
-  pos <- getPosition
-  updateState $ \s -> s{ stateLastStrPos = Just pos }
+  updateLastStrPos
   let spacesToNbr = map (\c -> if c == ' ' then '\160' else c)
   isSmart <- getOption readerSmart
   if isSmart
@@ -1821,9 +1818,7 @@ citeKey :: MarkdownParser (Bool, String)
 citeKey = try $ do
   -- make sure we're not right after an alphanumeric,
   -- since foo@bar.baz is probably an email address
-  lastStrPos <- stateLastStrPos <$> getState
-  pos <- getPosition
-  guard $ lastStrPos /= Just pos
+  guard =<< notAfterString
   suppress_author <- option False (char '-' >> return True)
   char '@'
   first <- letter <|> char '_'
diff --git a/src/Text/Pandoc/Readers/Org.hs b/src/Text/Pandoc/Readers/Org.hs
index 2e4a29beb..5dbcaee98 100644
--- a/src/Text/Pandoc/Readers/Org.hs
+++ b/src/Text/Pandoc/Readers/Org.hs
@@ -105,6 +105,10 @@ instance HasMeta OrgParserState where
   deleteMeta field st =
     st{ orgStateMeta = deleteMeta field $ orgStateMeta st }
 
+instance HasLastStrPosition OrgParserState where
+  getLastStrPos = orgStateLastStrPos
+  setLastStrPos pos st = st{ orgStateLastStrPos = Just pos }
+
 instance Default OrgParserState where
   def = defaultOrgParserState
 
@@ -1274,13 +1278,6 @@ afterEmphasisPreChar = do
   lastPrePos <- orgStateLastPreCharPos <$> getState
   return . fromMaybe True $ (== pos) <$> lastPrePos
 
--- | Whether we are right after the end of a string
-notAfterString :: OrgParser Bool
-notAfterString = do
-  pos <- getPosition
-  lastStrPos <- orgStateLastStrPos <$> getState
-  return $ lastStrPos /= Just pos
-
 -- | Whether the parser is right after a forbidden border char
 notAfterForbiddenBorderChar :: OrgParser Bool
 notAfterForbiddenBorderChar = do