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author | John MacFarlane <jgm@berkeley.edu> | 2014-04-09 09:34:44 -0700 |
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committer | John MacFarlane <jgm@berkeley.edu> | 2014-04-09 09:34:44 -0700 |
commit | 54e33a132bcbb353d6d85100dfe51e53fb3c5ace (patch) | |
tree | 14e62fce5145f086ec57f8fdf5e59a5619bfc98f /src | |
parent | e555a5703d4581f11c6b5020811bf60b5ec98c41 (diff) | |
parent | 030020236c85c736892a6f8e0dcefca1681e5ce0 (diff) | |
download | pandoc-54e33a132bcbb353d6d85100dfe51e53fb3c5ace.tar.gz |
Merge pull request #1226 from tarleb/org-emphasis-reader
Org reader: Precise rules for the recognition of markup
Diffstat (limited to 'src')
-rw-r--r-- | src/Text/Pandoc/Readers/Org.hs | 380 |
1 files changed, 260 insertions, 120 deletions
diff --git a/src/Text/Pandoc/Readers/Org.hs b/src/Text/Pandoc/Readers/Org.hs index 2bb6ee122..392b17bbc 100644 --- a/src/Text/Pandoc/Readers/Org.hs +++ b/src/Text/Pandoc/Readers/Org.hs @@ -32,11 +32,12 @@ import qualified Text.Pandoc.Builder as B import Text.Pandoc.Builder (Inlines, Blocks, trimInlines, (<>), HasMeta(..)) import Text.Pandoc.Definition import Text.Pandoc.Options -import Text.Pandoc.Parsing hiding (orderedListMarker, updateLastStrPos) +import qualified Text.Pandoc.Parsing as P +import Text.Pandoc.Parsing hiding (newline, orderedListMarker, updateLastStrPos) import Text.Pandoc.Shared (compactify') import Control.Applicative (pure, (<$>), (<$), (<*>), (<*), (*>), (<**>)) -import Control.Monad (guard, mzero) +import Control.Monad (guard, when) import Data.Char (toLower) import Data.Default import Data.List (foldl', isPrefixOf, isSuffixOf) @@ -47,49 +48,100 @@ import Data.Monoid (mconcat, mempty, mappend) readOrg :: ReaderOptions -- ^ Reader options -> String -- ^ String to parse (assuming @'\n'@ line endings) -> Pandoc -readOrg opts s = (readWith parseOrg) def{ orgOptions = opts } (s ++ "\n\n") +readOrg opts s = (readWith parseOrg) def{ orgStateOptions = opts } (s ++ "\n\n") type OrgParser = Parser [Char] OrgParserState +parseOrg:: OrgParser Pandoc +parseOrg = do + blocks' <- B.toList <$> parseBlocks + st <- getState + let meta = orgStateMeta st + return $ Pandoc meta $ filter (/= Null) blocks' + +-- +-- Parser State for Org +-- + -- | Org-mode parser state data OrgParserState = OrgParserState - { orgOptions :: ReaderOptions - , orgInlineCharStack :: [Char] - , orgLastStrPos :: Maybe SourcePos - , orgMeta :: Meta + { orgStateOptions :: ReaderOptions + , orgStateEmphasisCharStack :: [Char] + , orgStateEmphasisNewlines :: Maybe Int + , orgStateLastForbiddenCharPos :: Maybe SourcePos + , orgStateLastPreCharPos :: Maybe SourcePos + , orgStateLastStrPos :: Maybe SourcePos + , orgStateMeta :: Meta } deriving (Show) instance HasReaderOptions OrgParserState where - extractReaderOptions = orgOptions + extractReaderOptions = orgStateOptions instance HasMeta OrgParserState where setMeta field val st = - st{ orgMeta = setMeta field val $ orgMeta st } + st{ orgStateMeta = setMeta field val $ orgStateMeta st } deleteMeta field st = - st{ orgMeta = deleteMeta field $ orgMeta st } + st{ orgStateMeta = deleteMeta field $ orgStateMeta st } instance Default OrgParserState where def = defaultOrgParserState defaultOrgParserState :: OrgParserState defaultOrgParserState = OrgParserState - { orgOptions = def - , orgInlineCharStack = [] - , orgLastStrPos = Nothing - , orgMeta = nullMeta + { orgStateOptions = def + , orgStateEmphasisCharStack = [] + , orgStateEmphasisNewlines = Nothing + , orgStateLastForbiddenCharPos = Nothing + , orgStateLastPreCharPos = Nothing + , orgStateLastStrPos = Nothing + , orgStateMeta = nullMeta } updateLastStrPos :: OrgParser () updateLastStrPos = getPosition >>= \p -> - updateState $ \s -> s{ orgLastStrPos = Just p } + updateState $ \s -> s{ orgStateLastStrPos = Just p } +updateLastForbiddenCharPos :: OrgParser () +updateLastForbiddenCharPos = getPosition >>= \p -> + updateState $ \s -> s{ orgStateLastForbiddenCharPos = Just p} -parseOrg:: OrgParser Pandoc -parseOrg = do - blocks' <- B.toList <$> parseBlocks +updateLastPreCharPos :: OrgParser () +updateLastPreCharPos = getPosition >>= \p -> + updateState $ \s -> s{ orgStateLastPreCharPos = Just p} + +pushToInlineCharStack :: Char -> OrgParser () +pushToInlineCharStack c = updateState $ \st -> + st { orgStateEmphasisCharStack = c:(orgStateEmphasisCharStack st) } + +popInlineCharStack :: OrgParser () +popInlineCharStack = updateState $ \st -> + st { orgStateEmphasisCharStack = drop 1 . orgStateEmphasisCharStack $ st } + +surroundingEmphasisChar :: OrgParser [Char] +surroundingEmphasisChar = take 1 . drop 1 . orgStateEmphasisCharStack <$> getState + +startEmphasisNewlinesCounting :: Int -> OrgParser () +startEmphasisNewlinesCounting maxNewlines = updateState $ \s -> + s { orgStateEmphasisNewlines = Just maxNewlines } + +decEmphasisNewlinesCount :: OrgParser () +decEmphasisNewlinesCount = updateState $ \s -> + s{ orgStateEmphasisNewlines = (\n -> n - 1) <$> orgStateEmphasisNewlines s } + +newlinesCountWithinLimits :: OrgParser Bool +newlinesCountWithinLimits = do st <- getState - let meta = orgMeta st - return $ Pandoc meta $ filter (/= Null) blocks' + return $ ((< 0) <$> orgStateEmphasisNewlines st) /= Just True + +resetEmphasisNewlines :: OrgParser () +resetEmphasisNewlines = updateState $ \s -> + s{ orgStateEmphasisNewlines = Nothing } + +newline :: OrgParser Char +newline = + P.newline + <* updateLastPreCharPos + <* updateLastForbiddenCharPos -- -- parsing blocks @@ -218,7 +270,7 @@ commentLineStart = try $ mappend <$> many spaceChar <*> string "# " declarationLine :: OrgParser Blocks declarationLine = try $ do meta' <- B.setMeta <$> metaKey <*> metaValue <*> pure nullMeta - updateState $ \st -> st { orgMeta = orgMeta st <> meta' } + updateState $ \st -> st { orgStateMeta = orgStateMeta st <> meta' } return mempty metaValue :: OrgParser MetaValue @@ -449,22 +501,24 @@ anyLineNewline = (++ "\n") <$> anyLine -- inline :: OrgParser Inlines -inline = choice inlineParsers <?> "inline" - where inlineParsers = [ whitespace - , link - , str - , endline - , emph - , strong - , strikeout - , underline - , code - , math - , verbatim - , subscript - , superscript - , symbol - ] +inline = + choice [ whitespace + , link + , str + , endline + , emph + , strong + , strikeout + , underline + , code + , math + , verbatim + , subscript + , superscript + , symbol + ] <* (guard =<< newlinesCountWithinLimits) + <?> "inline" + -- treat these as potentially non-text when parsing inline: specialChars :: [Char] @@ -472,7 +526,10 @@ specialChars = "\"$'()*+-./:<=>[\\]^_{|}~" whitespace :: OrgParser Inlines -whitespace = B.space <$ skipMany1 spaceChar <?> "whitespace" +whitespace = B.space <$ skipMany1 spaceChar + <* updateLastPreCharPos + <* updateLastForbiddenCharPos + <?> "whitespace" str :: OrgParser Inlines str = B.str <$> many1 (noneOf $ specialChars ++ "\n\r ") @@ -492,6 +549,9 @@ endline = try $ do notFollowedBy' commentLineStart notFollowedBy' bulletListStart notFollowedBy' orderedListStart + decEmphasisNewlinesCount + guard =<< newlinesCountWithinLimits + updateLastPreCharPos return B.space link :: OrgParser Inlines @@ -500,42 +560,54 @@ link = explicitOrImageLink <|> selflinkOrImage <?> "link" explicitOrImageLink :: OrgParser Inlines explicitOrImageLink = try $ do char '[' - src <- enclosedRaw (char '[') (char ']') + src <- linkTarget title <- enclosedRaw (char '[') (char ']') title' <- parseFromString (mconcat <$> many inline) title char ']' - return $ if (isImage src) && (isImage title) + return $ if (isImageFilename src) && (isImageFilename title) then B.link src "" (B.image title "" "") else B.link src "" title' selflinkOrImage :: OrgParser Inlines selflinkOrImage = try $ do - src <- enclosedRaw (string "[[") (string "]]") - return $ if isImage src + src <- (char '[') *> linkTarget <* char ']' + return $ if isImageFilename src then B.image src "" "" else B.link src "" (B.str src) +linkTarget :: OrgParser String +linkTarget = enclosed (char '[') (char ']') (noneOf "\n\r]") + +isImageFilename :: String -> Bool +isImageFilename filename = + any (\x -> ('.':x) `isSuffixOf` filename) imageExtensions && + any (\x -> (x++":") `isPrefixOf` filename) protocols || + ':' `notElem` filename + where + imageExtensions = [ "jpeg" , "jpg" , "png" , "gif" , "svg" ] + protocols = [ "file", "http", "https" ] + emph :: OrgParser Inlines -emph = B.emph <$> inlinesEnclosedBy '/' +emph = B.emph <$> emphasisBetween '/' strong :: OrgParser Inlines -strong = B.strong <$> inlinesEnclosedBy '*' +strong = B.strong <$> emphasisBetween '*' strikeout :: OrgParser Inlines -strikeout = B.strikeout <$> inlinesEnclosedBy '+' +strikeout = B.strikeout <$> emphasisBetween '+' -- There is no underline, so we use strong instead. underline :: OrgParser Inlines -underline = B.strong <$> inlinesEnclosedBy '_' +underline = B.strong <$> emphasisBetween '_' code :: OrgParser Inlines -code = B.code <$> rawEnclosedBy '=' - -math :: OrgParser Inlines -math = B.math <$> rawEnclosedBy '$' +code = B.code <$> verbatimBetween '=' verbatim :: OrgParser Inlines -verbatim = B.rawInline "" <$> rawEnclosedBy '~' +verbatim = B.rawInline "" <$> verbatimBetween '~' + +math :: OrgParser Inlines +math = B.math <$> mathStringBetween '$' subscript :: OrgParser Inlines subscript = B.subscript <$> (try $ char '_' *> maybeGroupedByBraces) @@ -550,7 +622,72 @@ maybeGroupedByBraces = try $ ] symbol :: OrgParser Inlines -symbol = B.str . (: "") <$> oneOf specialChars +symbol = B.str . (: "") <$> (oneOf specialChars >>= updatePositions) + where updatePositions c + | c `elem` emphasisPreChars = c <$ updateLastPreCharPos + | c `elem` emphasisForbiddenBorderChars = c <$ updateLastForbiddenCharPos + | otherwise = return c + +emphasisBetween :: Char + -> OrgParser Inlines +emphasisBetween c = try $ do + startEmphasisNewlinesCounting emphasisAllowedNewlines + res <- enclosedInlines (emphasisStart c) (emphasisEnd c) + isTopLevelEmphasis <- null . orgStateEmphasisCharStack <$> getState + when isTopLevelEmphasis + resetEmphasisNewlines + return res + +verbatimBetween :: Char + -> OrgParser String +verbatimBetween c = try $ + emphasisStart c *> + many1TillNOrLessNewlines 1 (noneOf "\n\r") (emphasisEnd c) + +-- | Parses a raw string delimited by @c@ using Org's math rules +mathStringBetween :: Char + -> OrgParser String +mathStringBetween c = try $ do + mathStart c + body <- many1TillNOrLessNewlines mathAllowedNewlines + (noneOf (c:"\n\r")) + (lookAhead $ mathEnd c) + final <- mathEnd c + return $ body ++ [final] + +-- | Parses the start (opening character) of emphasis +emphasisStart :: Char -> OrgParser Char +emphasisStart c = try $ do + guard =<< afterEmphasisPreChar + guard =<< notAfterString + char c + lookAhead (noneOf emphasisForbiddenBorderChars) + pushToInlineCharStack c + return c + +-- | Parses the closing character of emphasis +emphasisEnd :: Char -> OrgParser Char +emphasisEnd c = try $ do + guard =<< notAfterForbiddenBorderChar + char c + eof <|> lookAhead (surroundingEmphasisChar >>= \x -> + oneOf (x ++ emphasisPostChars)) + *> return () + updateLastStrPos + popInlineCharStack + return c + +mathStart :: Char -> OrgParser Char +mathStart c = try $ do + char c <* notFollowedBy' (oneOf (c:mathForbiddenBorderChars)) + +mathEnd :: Char -> OrgParser Char +mathEnd c = try $ do + res <- noneOf (c:mathForbiddenBorderChars) + char c + eof <|> (lookAhead $ oneOf mathPostChars *> pure ()) + return res + enclosedInlines :: OrgParser a -> OrgParser b @@ -558,16 +695,6 @@ enclosedInlines :: OrgParser a enclosedInlines start end = try $ trimInlines . mconcat <$> enclosed start end inline --- FIXME: This is a hack -inlinesEnclosedBy :: Char - -> OrgParser Inlines -inlinesEnclosedBy c = try $ do - updateState $ \st -> st { orgInlineCharStack = c:(orgInlineCharStack st) } - res <- enclosedInlines (atStart (char c) <* endsOnThisOrNextLine c) - (atEnd $ char c) - updateState $ \st -> st { orgInlineCharStack = drop 1 . orgInlineCharStack $ st } - return res - enclosedRaw :: OrgParser a -> OrgParser b -> OrgParser String @@ -577,63 +704,76 @@ enclosedRaw start end = try $ spanningTwoLines = try $ anyLine >>= \f -> mappend (f <> " ") <$> onSingleLine -rawEnclosedBy :: Char - -> OrgParser String -rawEnclosedBy c = enclosedRaw (atStart $ char c) (atEnd $ char c) - --- succeeds only if we're not right after a str (ie. in middle of word) -atStart :: OrgParser a -> OrgParser a -atStart p = do - guard =<< not <$> isRightAfterString - p - --- | succeeds only if we're at the end of a word -atEnd :: OrgParser a -> OrgParser a -atEnd p = try $ do - p <* lookingAtEndOfWord - where lookingAtEndOfWord = - eof <|> const (return ()) =<< lookAhead . oneOf =<< postWordChars - -isRightAfterString :: OrgParser Bool -isRightAfterString = do +-- | Like many1Till, but parses at most @n+1@ lines. @p@ must not consume +-- newlines. +many1TillNOrLessNewlines :: Int + -> OrgParser Char + -> OrgParser a + -> OrgParser String +many1TillNOrLessNewlines n p end = try $ + nMoreLines (Just n) mempty >>= oneOrMore + where + nMoreLines Nothing cs = return cs + nMoreLines (Just 0) cs = try $ (cs ++) <$> finalLine + nMoreLines k cs = try $ (final k cs <|> rest k cs) + >>= uncurry nMoreLines + final _ cs = (\x -> (Nothing, cs ++ x)) <$> (try finalLine) + rest m cs = (\x -> (minus1 <$> m, cs ++ x ++ "\n")) <$> (try $ manyTill p P.newline) + finalLine = try $ manyTill p end + minus1 k = k - 1 + oneOrMore cs = guard (not $ null cs) *> return cs + +-- Org allows customization of the way it reads emphasis. We use the defaults +-- here (see, e.g., the Emacs Lisp variable `org-emphasis-regexp-components` +-- for details). + +-- | Chars allowed to occur before emphasis (spaces and newlines are ok, too) +emphasisPreChars :: [Char] +emphasisPreChars = "\t \"'({" + +-- | Chars allowed at after emphasis +emphasisPostChars :: [Char] +emphasisPostChars = "\t\n !\"'),-.:;?\\}" + +-- | Chars not allowed at the (inner) border of emphasis +emphasisForbiddenBorderChars :: [Char] +emphasisForbiddenBorderChars = "\t\n\r \"'," + +-- | The maximum number of newlines within +emphasisAllowedNewlines :: Int +emphasisAllowedNewlines = 1 + +-- LaTeX-style math: see `org-latex-regexps` for details + +-- | Chars allowed after an inline ($...$) math statement +mathPostChars :: [Char] +mathPostChars = "\t\n \"',-.:;?" + +-- | Chars not allowed at the (inner) border of math +mathForbiddenBorderChars :: [Char] +mathForbiddenBorderChars = "\t\n\r ,;.$" + +-- | Maximum number of newlines in an inline math statement +mathAllowedNewlines :: Int +mathAllowedNewlines = 2 + +-- | Whether we are right behind a char allowed before emphasis +afterEmphasisPreChar :: OrgParser Bool +afterEmphasisPreChar = do pos <- getPosition - st <- getState - -- the position `Nothing` isn't after a String, either, hence the double - -- negation - return $ not $ orgLastStrPos st /= Just pos + lastPrePos <- orgStateLastPreCharPos <$> getState + return $ lastPrePos == Nothing || lastPrePos == Just pos -postWordChars :: OrgParser [Char] -postWordChars = do - st <- getState - return $ "\t\n\r !\"'),-.:?}" ++ (take 1 . drop 1 . orgInlineCharStack $ st) - --- FIXME: These functions are hacks and should be replaced -endsOnThisOrNextLine :: Char - -> OrgParser () -endsOnThisOrNextLine c = do - inp <- getInput - let doOtherwise = \rest -> endsOnThisLine rest c (const mzero) - endsOnThisLine inp c doOtherwise - -endsOnThisLine :: [Char] - -> Char - -> ([Char] -> OrgParser ()) - -> OrgParser () -endsOnThisLine input c doOnOtherLines = do - postWordChars' <- postWordChars - case break (`elem` c:"\n") input of - (_,'\n':rest) -> doOnOtherLines rest - (_,_:[]) -> return () - (_,_:rest@(n:_)) -> if n `elem` postWordChars' - then return () - else endsOnThisLine rest c doOnOtherLines - _ -> mzero - -isImage :: String -> Bool -isImage filename = - any (\x -> ('.':x) `isSuffixOf` filename) imageExtensions && - any (\x -> (x++":") `isPrefixOf` filename) protocols || - ':' `notElem` filename - where - imageExtensions = [ "jpeg" , "jpg" , "png" , "gif" , "svg" ] - protocols = [ "file", "http", "https" ] +-- | 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 + pos <- getPosition + lastFBCPos <- orgStateLastForbiddenCharPos <$> getState + return $ lastFBCPos /= Just pos |