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Diffstat (limited to 'src/Text/Pandoc/Readers/Markdown.hs')
| -rw-r--r-- | src/Text/Pandoc/Readers/Markdown.hs | 909 |
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diff --git a/src/Text/Pandoc/Readers/Markdown.hs b/src/Text/Pandoc/Readers/Markdown.hs new file mode 100644 index 000000000..df84c0ac7 --- /dev/null +++ b/src/Text/Pandoc/Readers/Markdown.hs @@ -0,0 +1,909 @@ +{- +Copyright (C) 2006-7 John MacFarlane <jgm@berkeley.edu> + +This program is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 2 of the License, or +(at your option) any later version. + +This program is distributed in the hope that it will be useful, +but WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +GNU General Public License for more details. + +You should have received a copy of the GNU General Public License +along with this program; if not, write to the Free Software +Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA +-} + +{- | + Module : Text.Pandoc.Readers.Markdown + Copyright : Copyright (C) 2006-7 John MacFarlane + License : GNU GPL, version 2 or above + + Maintainer : John MacFarlane <jgm@berkeley.edu> + Stability : alpha + Portability : portable + +Conversion of markdown-formatted plain text to 'Pandoc' document. +-} +module Text.Pandoc.Readers.Markdown ( + readMarkdown + ) where + +import Data.List ( transpose, isPrefixOf, isSuffixOf, lookup, sortBy ) +import Data.Ord ( comparing ) +import Data.Char ( isAlphaNum ) +import Network.URI ( isURI ) +import Text.Pandoc.Definition +import Text.Pandoc.Shared +import Text.Pandoc.Readers.LaTeX ( rawLaTeXInline, rawLaTeXEnvironment ) +import Text.Pandoc.Readers.HTML ( rawHtmlBlock, anyHtmlBlockTag, + anyHtmlInlineTag, anyHtmlTag, + anyHtmlEndTag, htmlEndTag, extractTagType, + htmlBlockElement ) +import Text.Pandoc.CharacterReferences ( decodeCharacterReferences ) +import Text.ParserCombinators.Parsec + +-- | Read markdown from an input string and return a Pandoc document. +readMarkdown :: ParserState -> String -> Pandoc +readMarkdown state str = (readWith parseMarkdown) state (str ++ "\n\n") + +-- +-- Constants and data structure definitions +-- + +spaceChars = " \t" +bulletListMarkers = "*+-" +hruleChars = "*-_" +setextHChars = "=-" + +-- treat these as potentially non-text when parsing inline: +specialChars = "\\[]*_~`<>$!^-.&'\"" + +-- +-- auxiliary functions +-- + +indentSpaces = try $ do + state <- getState + let tabStop = stateTabStop state + try (count tabStop (char ' ')) <|> + (many (char ' ') >> string "\t") <?> "indentation" + +nonindentSpaces = do + state <- getState + let tabStop = stateTabStop state + sps <- many (char ' ') + if length sps < tabStop + then return sps + else unexpected "indented line" + +-- | Fail unless we're at beginning of a line. +failUnlessBeginningOfLine = do + pos <- getPosition + if sourceColumn pos == 1 then return () else fail "not beginning of line" + +-- | Fail unless we're in "smart typography" mode. +failUnlessSmart = do + state <- getState + if stateSmart state then return () else fail "Smart typography feature" + +-- | Parse an inline Str element with a given content. +inlineString str = try $ do + (Str res) <- inline + if res == str then return res else fail $ "unexpected Str content" + +-- | Parse a sequence of inline elements between a string +-- @opener@ and a string @closer@, including inlines +-- between balanced pairs of @opener@ and a @closer@. +inlinesInBalanced :: String -> String -> GenParser Char ParserState [Inline] +inlinesInBalanced opener closer = try $ do + string opener + result <- manyTill ( (do lookAhead (inlineString opener) + -- because it might be a link... + bal <- inlinesInBalanced opener closer + return $ [Str opener] ++ bal ++ [Str closer]) + <|> (count 1 inline)) + (try (string closer)) + return $ concat result + +-- +-- document structure +-- + +titleLine = try $ char '%' >> skipSpaces >> manyTill inline newline + +authorsLine = try $ do + char '%' + skipSpaces + authors <- sepEndBy (many1 (noneOf ",;\n")) (oneOf ",;") + newline + return $ map (decodeCharacterReferences . removeLeadingTrailingSpace) authors + +dateLine = try $ do + char '%' + skipSpaces + date <- many (noneOf "\n") + newline + return $ decodeCharacterReferences $ removeTrailingSpace date + +titleBlock = try $ do + failIfStrict + title <- option [] titleLine + author <- option [] authorsLine + date <- option "" dateLine + optional blanklines + return (title, author, date) + +parseMarkdown = do + -- markdown allows raw HTML + updateState (\state -> state { stateParseRaw = True }) + startPos <- getPosition + -- go through once just to get list of reference keys + -- docMinusKeys is the raw document with blanks where the keys were... + docMinusKeys <- manyTill (referenceKey <|> lineClump) eof >>= + return . concat + setInput docMinusKeys + setPosition startPos + st <- getState + -- go through again for notes unless strict... + if stateStrict st + then return () + else do docMinusNotes <- manyTill (noteBlock <|> lineClump) eof >>= + return . concat + st <- getState + let reversedNotes = stateNotes st + updateState $ \st -> st { stateNotes = reverse reversedNotes } + setInput docMinusNotes + setPosition startPos + -- now parse it for real... + (title, author, date) <- option ([],[],"") titleBlock + blocks <- parseBlocks + return $ Pandoc (Meta title author date) $ filter (/= Null) blocks + +-- +-- initial pass for references and notes +-- + +referenceKey = try $ do + startPos <- getPosition + nonindentSpaces + label <- reference + char ':' + skipSpaces + optional (char '<') + src <- many (noneOf "> \n\t") + optional (char '>') + tit <- option "" referenceTitle + blanklines + endPos <- getPosition + let newkey = (label, (removeTrailingSpace src, tit)) + st <- getState + let oldkeys = stateKeys st + updateState $ \st -> st { stateKeys = newkey : oldkeys } + -- return blanks so line count isn't affected + return $ replicate (sourceLine endPos - sourceLine startPos) '\n' + +referenceTitle = try $ do + (many1 spaceChar >> option '\n' newline) <|> newline + skipSpaces + tit <- (charsInBalanced '(' ')' >>= return . unwords . words) + <|> do delim <- char '\'' <|> char '"' + manyTill anyChar (try (char delim >> skipSpaces >> + notFollowedBy (noneOf ")\n"))) + return $ decodeCharacterReferences tit + +noteMarker = string "[^" >> manyTill (noneOf " \t\n") (char ']') + +rawLine = do + notFollowedBy blankline + notFollowedBy' noteMarker + contents <- many1 nonEndline + end <- option "" (newline >> optional indentSpaces >> return "\n") + return $ contents ++ end + +rawLines = many1 rawLine >>= return . concat + +noteBlock = try $ do + startPos <- getPosition + ref <- noteMarker + char ':' + optional blankline + optional indentSpaces + raw <- sepBy rawLines (try (blankline >> indentSpaces)) + optional blanklines + endPos <- getPosition + -- parse the extracted text, which may contain various block elements: + contents <- parseFromString parseBlocks $ (joinWithSep "\n" raw) ++ "\n\n" + let newnote = (ref, contents) + st <- getState + let oldnotes = stateNotes st + updateState $ \st -> st { stateNotes = newnote : oldnotes } + -- return blanks so line count isn't affected + return $ replicate (sourceLine endPos - sourceLine startPos) '\n' + +-- +-- parsing blocks +-- + +parseBlocks = manyTill block eof + +block = choice [ header + , table + , codeBlock + , hrule + , list + , blockQuote + , htmlBlock + , rawLaTeXEnvironment' + , para + , plain + , nullBlock ] <?> "block" + +-- +-- header blocks +-- + +header = atxHeader <|> setextHeader <?> "header" + +atxHeader = try $ do + level <- many1 (char '#') >>= return . length + notFollowedBy (char '.' <|> char ')') -- this would be a list + skipSpaces + text <- manyTill inline atxClosing >>= return . normalizeSpaces + return $ Header level text + +atxClosing = try $ skipMany (char '#') >> blanklines + +setextHeader = try $ do + -- first, see if this block has any chance of being a setextHeader: + lookAhead (anyLine >> oneOf setextHChars) + text <- many1Till inline newline >>= return . normalizeSpaces + level <- choice $ zipWith + (\ch lev -> try (many1 $ char ch) >> blanklines >> return lev) + setextHChars [1..(length setextHChars)] + return $ Header level text + +-- +-- hrule block +-- + +hrule = try $ do + skipSpaces + start <- oneOf hruleChars + count 2 (skipSpaces >> char start) + skipMany (skipSpaces >> char start) + newline + optional blanklines + return HorizontalRule + +-- +-- code blocks +-- + +indentedLine = indentSpaces >> manyTill anyChar newline >>= return . (++ "\n") + +codeBlock = do + contents <- many1 (indentedLine <|> + try (do b <- blanklines + l <- indentedLine + return $ b ++ l)) + optional blanklines + return $ CodeBlock $ stripTrailingNewlines $ concat contents + +-- +-- block quotes +-- + +emacsBoxQuote = try $ do + failIfStrict + string ",----" + manyTill anyChar newline + raw <- manyTill + (try (char '|' >> optional (char ' ') >> manyTill anyChar newline)) + (try (string "`----")) + blanklines + return raw + +emailBlockQuoteStart = try $ nonindentSpaces >> char '>' >>~ optional (char ' ') + +emailBlockQuote = try $ do + emailBlockQuoteStart + raw <- sepBy (many (nonEndline <|> + (try (endline >> notFollowedBy emailBlockQuoteStart >> + return '\n')))) + (try (newline >> emailBlockQuoteStart)) + newline <|> (eof >> return '\n') + optional blanklines + return raw + +blockQuote = do + raw <- emailBlockQuote <|> emacsBoxQuote + -- parse the extracted block, which may contain various block elements: + contents <- parseFromString parseBlocks $ (joinWithSep "\n" raw) ++ "\n\n" + return $ BlockQuote contents + +-- +-- list blocks +-- + +list = choice [ bulletList, orderedList, definitionList ] <?> "list" + +bulletListStart = try $ do + optional newline -- if preceded by a Plain block in a list context + nonindentSpaces + notFollowedBy' hrule -- because hrules start out just like lists + oneOf bulletListMarkers + spaceChar + skipSpaces + +anyOrderedListStart = try $ do + optional newline -- if preceded by a Plain block in a list context + nonindentSpaces + notFollowedBy $ string "p." >> spaceChar >> digit -- page number + state <- getState + if stateStrict state + then do many1 digit + char '.' + spaceChar + return (1, DefaultStyle, DefaultDelim) + else anyOrderedListMarker >>~ spaceChar + +orderedListStart style delim = try $ do + optional newline -- if preceded by a Plain block in a list context + nonindentSpaces + state <- getState + num <- if stateStrict state + then do many1 digit + char '.' + return 1 + else orderedListMarker style delim + if delim == Period && (style == UpperAlpha || (style == UpperRoman && + num `elem` [1, 5, 10, 50, 100, 500, 1000])) + then char '\t' <|> (spaceChar >> spaceChar) + else spaceChar + skipSpaces + +-- parse a line of a list item (start = parser for beginning of list item) +listLine start = try $ do + notFollowedBy' start + notFollowedBy blankline + notFollowedBy' (do indentSpaces + many (spaceChar) + bulletListStart <|> (anyOrderedListStart >> return ())) + line <- manyTill anyChar newline + return $ line ++ "\n" + +-- parse raw text for one list item, excluding start marker and continuations +rawListItem start = try $ do + start + result <- many1 (listLine start) + blanks <- many blankline + return $ concat result ++ blanks + +-- continuation of a list item - indented and separated by blankline +-- or (in compact lists) endline. +-- note: nested lists are parsed as continuations +listContinuation start = try $ do + lookAhead indentSpaces + result <- many1 (listContinuationLine start) + blanks <- many blankline + return $ concat result ++ blanks + +listContinuationLine start = try $ do + notFollowedBy blankline + notFollowedBy' start + optional indentSpaces + result <- manyTill anyChar newline + return $ result ++ "\n" + +listItem start = try $ do + first <- rawListItem start + continuations <- many (listContinuation start) + -- parsing with ListItemState forces markers at beginning of lines to + -- count as list item markers, even if not separated by blank space. + -- see definition of "endline" + state <- getState + let oldContext = stateParserContext state + setState $ state {stateParserContext = ListItemState} + -- parse the extracted block, which may contain various block elements: + let raw = concat (first:continuations) + contents <- parseFromString parseBlocks raw + updateState (\st -> st {stateParserContext = oldContext}) + return contents + +orderedList = try $ do + (start, style, delim) <- lookAhead anyOrderedListStart + items <- many1 (listItem (orderedListStart style delim)) + return $ OrderedList (start, style, delim) $ compactify items + +bulletList = many1 (listItem bulletListStart) >>= + return . BulletList . compactify + +-- definition lists + +definitionListItem = try $ do + notFollowedBy blankline + notFollowedBy' indentSpaces + -- first, see if this has any chance of being a definition list: + lookAhead (anyLine >> char ':') + term <- manyTill inline newline + raw <- many1 defRawBlock + state <- getState + let oldContext = stateParserContext state + -- parse the extracted block, which may contain various block elements: + contents <- parseFromString parseBlocks $ concat raw + updateState (\st -> st {stateParserContext = oldContext}) + return ((normalizeSpaces term), contents) + +defRawBlock = try $ do + char ':' + state <- getState + let tabStop = stateTabStop state + try (count (tabStop - 1) (char ' ')) <|> (many (char ' ') >> string "\t") + firstline <- anyLine + rawlines <- many (notFollowedBy blankline >> indentSpaces >> anyLine) + trailing <- option "" blanklines + return $ firstline ++ "\n" ++ unlines rawlines ++ trailing + +definitionList = do + failIfStrict + items <- many1 definitionListItem + let (terms, defs) = unzip items + let defs' = compactify defs + let items' = zip terms defs' + return $ DefinitionList items' + +-- +-- paragraph block +-- + +para = try $ do + result <- many1 inline + newline + blanklines <|> do st <- getState + if stateStrict st + then lookAhead (blockQuote <|> header) >> return "" + else lookAhead emacsBoxQuote >> return "" + return $ Para $ normalizeSpaces result + +plain = many1 inline >>= return . Plain . normalizeSpaces + +-- +-- raw html +-- + +htmlElement = strictHtmlBlock <|> htmlBlockElement <?> "html element" + +htmlBlock = do + st <- getState + if stateStrict st + then try $ do failUnlessBeginningOfLine + first <- htmlElement + finalSpace <- many (oneOf spaceChars) + finalNewlines <- many newline + return $ RawHtml $ first ++ finalSpace ++ finalNewlines + else rawHtmlBlocks + +-- True if tag is self-closing +isSelfClosing tag = + isSuffixOf "/>" $ filter (not . (`elem` " \n\t")) tag + +strictHtmlBlock = try $ do + tag <- anyHtmlBlockTag + let tag' = extractTagType tag + if isSelfClosing tag || tag' == "hr" + then return tag + else do contents <- many (notFollowedBy' (htmlEndTag tag') >> + (htmlElement <|> (count 1 anyChar))) + end <- htmlEndTag tag' + return $ tag ++ concat contents ++ end + +rawHtmlBlocks = do + htmlBlocks <- many1 rawHtmlBlock + let combined = concatMap (\(RawHtml str) -> str) htmlBlocks + let combined' = if not (null combined) && last combined == '\n' + then init combined -- strip extra newline + else combined + return $ RawHtml combined' + +-- +-- LaTeX +-- + +rawLaTeXEnvironment' = failIfStrict >> rawLaTeXEnvironment + +-- +-- Tables +-- + +-- Parse a dashed line with optional trailing spaces; return its length +-- and the length including trailing space. +dashedLine ch = do + dashes <- many1 (char ch) + sp <- many spaceChar + return $ (length dashes, length $ dashes ++ sp) + +-- Parse a table header with dashed lines of '-' preceded by +-- one line of text. +simpleTableHeader = try $ do + rawContent <- anyLine + initSp <- nonindentSpaces + dashes <- many1 (dashedLine '-') + newline + let (lengths, lines) = unzip dashes + let indices = scanl (+) (length initSp) lines + let rawHeads = tail $ splitByIndices (init indices) rawContent + let aligns = zipWith alignType (map (\a -> [a]) rawHeads) lengths + return (rawHeads, aligns, indices) + +-- Parse a table footer - dashed lines followed by blank line. +tableFooter = try $ nonindentSpaces >> many1 (dashedLine '-') >> blanklines + +-- Parse a table separator - dashed line. +tableSep = try $ nonindentSpaces >> many1 (dashedLine '-') >> string "\n" + +-- Parse a raw line and split it into chunks by indices. +rawTableLine indices = do + notFollowedBy' (blanklines <|> tableFooter) + line <- many1Till anyChar newline + return $ map removeLeadingTrailingSpace $ tail $ + splitByIndices (init indices) line + +-- Parse a table line and return a list of lists of blocks (columns). +tableLine indices = rawTableLine indices >>= mapM (parseFromString (many plain)) + +-- Parse a multiline table row and return a list of blocks (columns). +multilineRow indices = do + colLines <- many1 (rawTableLine indices) + optional blanklines + let cols = map unlines $ transpose colLines + mapM (parseFromString (many plain)) cols + +-- Calculate relative widths of table columns, based on indices +widthsFromIndices :: Int -- Number of columns on terminal + -> [Int] -- Indices + -> [Float] -- Fractional relative sizes of columns +widthsFromIndices _ [] = [] +widthsFromIndices numColumns indices = + let lengths = zipWith (-) indices (0:indices) + totLength = sum lengths + quotient = if totLength > numColumns + then fromIntegral totLength + else fromIntegral numColumns + fracs = map (\l -> (fromIntegral l) / quotient) lengths in + tail fracs + +-- Parses a table caption: inlines beginning with 'Table:' +-- and followed by blank lines. +tableCaption = try $ do + nonindentSpaces + string "Table:" + result <- many1 inline + blanklines + return $ normalizeSpaces result + +-- Parse a table using 'headerParser', 'lineParser', and 'footerParser'. +tableWith headerParser lineParser footerParser = try $ do + (rawHeads, aligns, indices) <- headerParser + lines <- many1Till (lineParser indices) footerParser + caption <- option [] tableCaption + heads <- mapM (parseFromString (many plain)) rawHeads + state <- getState + let numColumns = stateColumns state + let widths = widthsFromIndices numColumns indices + return $ Table caption aligns widths heads lines + +-- Parse a simple table with '---' header and one line per row. +simpleTable = tableWith simpleTableHeader tableLine blanklines + +-- Parse a multiline table: starts with row of '-' on top, then header +-- (which may be multiline), then the rows, +-- which may be multiline, separated by blank lines, and +-- ending with a footer (dashed line followed by blank line). +multilineTable = tableWith multilineTableHeader multilineRow tableFooter + +multilineTableHeader = try $ do + tableSep + rawContent <- many1 (notFollowedBy' tableSep >> many1Till anyChar newline) + initSp <- nonindentSpaces + dashes <- many1 (dashedLine '-') + newline + let (lengths, lines) = unzip dashes + let indices = scanl (+) (length initSp) lines + let rawHeadsList = transpose $ map + (\ln -> tail $ splitByIndices (init indices) ln) + rawContent + let rawHeads = map (joinWithSep " ") rawHeadsList + let aligns = zipWith alignType rawHeadsList lengths + return ((map removeLeadingTrailingSpace rawHeads), aligns, indices) + +-- Returns an alignment type for a table, based on a list of strings +-- (the rows of the column header) and a number (the length of the +-- dashed line under the rows. +alignType :: [String] -> Int -> Alignment +alignType [] len = AlignDefault +alignType strLst len = + let str = head $ sortBy (comparing length) $ + map removeTrailingSpace strLst + leftSpace = if null str then False else (str !! 0) `elem` " \t" + rightSpace = length str < len || (str !! (len - 1)) `elem` " \t" + in case (leftSpace, rightSpace) of + (True, False) -> AlignRight + (False, True) -> AlignLeft + (True, True) -> AlignCenter + (False, False) -> AlignDefault + +table = failIfStrict >> (simpleTable <|> multilineTable) <?> "table" + +-- +-- inline +-- + +inline = choice [ str + , smartPunctuation + , whitespace + , endline + , code + , charRef + , strong + , emph + , note + , inlineNote + , link + , image + , math + , strikeout + , superscript + , subscript + , autoLink + , rawHtmlInline' + , rawLaTeXInline' + , escapedChar + , symbol + , ltSign ] <?> "inline" + +escapedChar = do + char '\\' + state <- getState + result <- option '\\' $ if stateStrict state + then oneOf "\\`*_{}[]()>#+-.!~" + else satisfy (not . isAlphaNum) + return $ Str [result] + +ltSign = do + st <- getState + if stateStrict st + then char '<' + else notFollowedBy' rawHtmlBlocks >> char '<' -- unless it starts html + return $ Str ['<'] + +specialCharsMinusLt = filter (/= '<') specialChars + +symbol = do + result <- oneOf specialCharsMinusLt + return $ Str [result] + +-- parses inline code, between n `s and n `s +code = try $ do + starts <- many1 (char '`') + skipSpaces + result <- many1Till (many1 (noneOf "`\n") <|> many1 (char '`') <|> + (char '\n' >> return " ")) + (try (skipSpaces >> count (length starts) (char '`') >> + notFollowedBy (char '`'))) + return $ Code $ removeLeadingTrailingSpace $ concat result + +mathWord = many1 ((noneOf " \t\n\\$") <|> + (try (char '\\') >>~ notFollowedBy (char '$'))) + +math = try $ do + failIfStrict + char '$' + notFollowedBy space + words <- sepBy1 mathWord (many1 space) + char '$' + return $ TeX ("$" ++ (joinWithSep " " words) ++ "$") + +emph = ((enclosed (char '*') (char '*') inline) <|> + (enclosed (char '_') (char '_' >> notFollowedBy alphaNum) inline)) >>= + return . Emph . normalizeSpaces + +strong = ((enclosed (string "**") (try $ string "**") inline) <|> + (enclosed (string "__") (try $ string "__") inline)) >>= + return . Strong . normalizeSpaces + +strikeout = failIfStrict >> enclosed (string "~~") (try $ string "~~") inline >>= + return . Strikeout . normalizeSpaces + +superscript = failIfStrict >> enclosed (char '^') (char '^') + (notFollowedBy' whitespace >> inline) >>= -- may not contain Space + return . Superscript + +subscript = failIfStrict >> enclosed (char '~') (char '~') + (notFollowedBy' whitespace >> inline) >>= -- may not contain Space + return . Subscript + +smartPunctuation = failUnlessSmart >> + choice [ quoted, apostrophe, dash, ellipses ] + +apostrophe = (char '\'' <|> char '\8217') >> return Apostrophe + +quoted = doubleQuoted <|> singleQuoted + +withQuoteContext context parser = do + oldState <- getState + let oldQuoteContext = stateQuoteContext oldState + setState oldState { stateQuoteContext = context } + result <- parser + newState <- getState + setState newState { stateQuoteContext = oldQuoteContext } + return result + +singleQuoted = try $ do + singleQuoteStart + withQuoteContext InSingleQuote $ many1Till inline singleQuoteEnd >>= + return . Quoted SingleQuote . normalizeSpaces + +doubleQuoted = try $ do + doubleQuoteStart + withQuoteContext InDoubleQuote $ many1Till inline doubleQuoteEnd >>= + return . Quoted DoubleQuote . normalizeSpaces + +failIfInQuoteContext context = do + st <- getState + if stateQuoteContext st == context + then fail "already inside quotes" + else return () + +singleQuoteStart = do + failIfInQuoteContext InSingleQuote + char '\8216' <|> + do char '\'' + notFollowedBy (oneOf ")!],.;:-? \t\n") + notFollowedBy (try (oneOfStrings ["s","t","m","ve","ll","re"] >> + satisfy (not . isAlphaNum))) -- possess/contraction + return '\'' + +singleQuoteEnd = (char '\'' <|> char '\8217') >> notFollowedBy alphaNum + +doubleQuoteStart = failIfInQuoteContext InDoubleQuote >> + (char '"' <|> char '\8220') >> + notFollowedBy (oneOf " \t\n") + +doubleQuoteEnd = char '"' <|> char '\8221' + +ellipses = oneOfStrings ["...", " . . . ", ". . .", " . . ."] >> return Ellipses + +dash = enDash <|> emDash + +enDash = try $ char '-' >> notFollowedBy (noneOf "0123456789") >> return EnDash + +emDash = try $ skipSpaces >> oneOfStrings ["---", "--"] >> + skipSpaces >> return EmDash + +whitespace = do + sps <- many1 (oneOf spaceChars) + if length sps >= 2 + then option Space (endline >> return LineBreak) + else return Space <?> "whitespace" + +nonEndline = satisfy (/='\n') + +strChar = noneOf (specialChars ++ spaceChars ++ "\n") + +str = many1 strChar >>= return . Str + +-- an endline character that can be treated as a space, not a structural break +endline = try $ do + newline + notFollowedBy blankline + st <- getState + if stateStrict st + then do notFollowedBy emailBlockQuoteStart + notFollowedBy (char '#') -- atx header + else return () + -- parse potential list-starts differently if in a list: + if stateParserContext st == ListItemState + then notFollowedBy' (bulletListStart <|> + (anyOrderedListStart >> return ())) + else return () + return Space + +-- +-- links +-- + +-- a reference label for a link +reference = notFollowedBy' (string "[^") >> -- footnote reference + inlinesInBalanced "[" "]" >>= (return . normalizeSpaces) + +-- source for a link, with optional title +source = try $ do + char '(' + optional (char '<') + src <- many (noneOf ")> \t\n") + optional (char '>') + tit <- option "" linkTitle + skipSpaces + char ')' + return (removeTrailingSpace src, tit) + +linkTitle = try $ do + (many1 spaceChar >> option '\n' newline) <|> newline + skipSpaces + delim <- char '\'' <|> char '"' + tit <- manyTill anyChar (try (char delim >> skipSpaces >> + notFollowedBy (noneOf ")\n"))) + return $ decodeCharacterReferences tit + +link = try $ do + label <- reference + src <- source <|> referenceLink label + return $ Link label src + +-- a link like [this][ref] or [this][] or [this] +referenceLink label = do + ref <- option [] (try (optional (char ' ') >> + optional (newline >> skipSpaces) >> reference)) + let ref' = if null ref then label else ref + state <- getState + case lookupKeySrc (stateKeys state) ref' of + Nothing -> fail "no corresponding key" + Just target -> return target + +emailAddress = try $ do + name <- many1 (alphaNum <|> char '+') + char '@' + first <- many1 alphaNum + rest <- many1 (char '.' >> many1 alphaNum) + return $ "mailto:" ++ name ++ "@" ++ joinWithSep "." (first:rest) + +uri = try $ do + str <- many1 (noneOf "\n\t >") + if isURI str + then return str + else fail "not a URI" + +autoLink = try $ do + char '<' + src <- uri <|> emailAddress + char '>' + let src' = if "mailto:" `isPrefixOf` src + then drop 7 src + else src + st <- getState + return $ if stateStrict st + then Link [Str src'] (src, "") + else Link [Code src'] (src, "") + +image = try $ do + char '!' + (Link label src) <- link + return $ Image label src + +note = try $ do + failIfStrict + ref <- noteMarker + state <- getState + let notes = stateNotes state + case lookup ref notes of + Nothing -> fail "note not found" + Just contents -> return $ Note contents + +inlineNote = try $ do + failIfStrict + char '^' + contents <- inlinesInBalanced "[" "]" + return $ Note [Para contents] + +rawLaTeXInline' = failIfStrict >> rawLaTeXInline + +rawHtmlInline' = do + st <- getState + result <- choice $ if stateStrict st + then [htmlBlockElement, anyHtmlTag, anyHtmlEndTag] + else [htmlBlockElement, anyHtmlInlineTag] + return $ HtmlInline result + |