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|
{-
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 <- many (referenceKey <|> lineClump) >>= return . concat
setInput docMinusKeys
setPosition startPos
st <- getState
-- go through again for notes unless strict...
if stateStrict st
then return ()
else do docMinusNotes <- many (noteBlock <|> lineClump) >>= 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
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