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Diffstat (limited to 'Text/Pandoc/Readers/LaTeX.hs')
| -rw-r--r-- | Text/Pandoc/Readers/LaTeX.hs | 652 |
1 files changed, 652 insertions, 0 deletions
diff --git a/Text/Pandoc/Readers/LaTeX.hs b/Text/Pandoc/Readers/LaTeX.hs new file mode 100644 index 000000000..79f9fc0f7 --- /dev/null +++ b/Text/Pandoc/Readers/LaTeX.hs @@ -0,0 +1,652 @@ +{- +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.LaTeX + 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 LaTeX to 'Pandoc' document. +-} +module Text.Pandoc.Readers.LaTeX ( + readLaTeX, + rawLaTeXInline, + rawLaTeXEnvironment + ) where + +import Text.ParserCombinators.Parsec +import Text.Pandoc.Definition +import Text.Pandoc.Shared +import Data.Maybe ( fromMaybe ) +import Data.Char ( chr ) +import Data.List ( isPrefixOf, isSuffixOf ) + +-- | Parse LaTeX from string and return 'Pandoc' document. +readLaTeX :: ParserState -- ^ Parser state, including options for parser + -> String -- ^ String to parse + -> Pandoc +readLaTeX = readWith parseLaTeX + +-- characters with special meaning +specialChars = "\\`$%^&_~#{}\n \t|<>'\"-" + +-- +-- utility functions +-- + +-- | Returns text between brackets and its matching pair. +bracketedText openB closeB = do + result <- charsInBalanced' openB closeB + return $ [openB] ++ result ++ [closeB] + +-- | Returns an option or argument of a LaTeX command. +optOrArg = bracketedText '{' '}' <|> bracketedText '[' ']' + +-- | True if the string begins with '{'. +isArg ('{':rest) = True +isArg other = False + +-- | Returns list of options and arguments of a LaTeX command. +commandArgs = many optOrArg + +-- | Parses LaTeX command, returns (name, star, list of options or arguments). +command = do + char '\\' + name <- many1 letter + star <- option "" (string "*") -- some commands have starred versions + args <- commandArgs + return (name, star, args) + +begin name = try $ do + string $ "\\begin{" ++ name ++ "}" + optional commandArgs + spaces + return name + +end name = try $ do + string $ "\\end{" ++ name ++ "}" + spaces + return name + +-- | Returns a list of block elements containing the contents of an +-- environment. +environment name = try $ begin name >> spaces >> manyTill block (end name) + +anyEnvironment = try $ do + string "\\begin{" + name <- many letter + star <- option "" (string "*") -- some environments have starred variants + char '}' + optional commandArgs + spaces + contents <- manyTill block (end (name ++ star)) + return $ BlockQuote contents + +-- +-- parsing documents +-- + +-- | Process LaTeX preamble, extracting metadata. +processLaTeXPreamble = try $ manyTill + (choice [bibliographic, comment, unknownCommand, nullBlock]) + (try (string "\\begin{document}")) >> + spaces + +-- | Parse LaTeX and return 'Pandoc'. +parseLaTeX = do + optional processLaTeXPreamble -- preamble might not be present (fragment) + spaces + blocks <- parseBlocks + spaces + optional $ try (string "\\end{document}" >> many anyChar) + -- might not be present (fragment) + spaces + eof + state <- getState + let blocks' = filter (/= Null) blocks + let title' = stateTitle state + let authors' = stateAuthors state + let date' = stateDate state + return $ Pandoc (Meta title' authors' date') blocks' + +-- +-- parsing blocks +-- + +parseBlocks = spaces >> many block + +block = choice [ hrule + , codeBlock + , header + , list + , blockQuote + , mathBlock + , comment + , bibliographic + , para + , specialEnvironment + , itemBlock + , unknownEnvironment + , unknownCommand ] <?> "block" + +-- +-- header blocks +-- + +header = try $ do + char '\\' + subs <- many (try (string "sub")) + string "section" + optional (char '*') + char '{' + title <- manyTill inline (char '}') + spaces + return $ Header (length subs + 1) (normalizeSpaces title) + +-- +-- hrule block +-- + +hrule = oneOfStrings [ "\\begin{center}\\rule{3in}{0.4pt}\\end{center}\n\n", + "\\newpage" ] >> spaces >> return HorizontalRule + +-- +-- code blocks +-- + +codeBlock = codeBlock1 <|> codeBlock2 + +codeBlock1 = try $ do + string "\\begin{verbatim}" -- don't use begin function because it + -- gobbles whitespace + optional blanklines -- we want to gobble blank lines, but not + -- leading space + contents <- manyTill anyChar (try (string "\\end{verbatim}")) + spaces + return $ CodeBlock (stripTrailingNewlines contents) + +codeBlock2 = try $ do + string "\\begin{Verbatim}" -- used by fancyvrb package + option "" blanklines + contents <- manyTill anyChar (try (string "\\end{Verbatim}")) + spaces + return $ CodeBlock (stripTrailingNewlines contents) + +-- +-- block quotes +-- + +blockQuote = (environment "quote" <|> environment "quotation") >>~ spaces >>= + return . BlockQuote + +-- +-- math block +-- + +mathBlock = mathBlockWith (begin "equation") (end "equation") <|> + mathBlockWith (begin "displaymath") (end "displaymath") <|> + mathBlockWith (try $ string "\\[") (try $ string "\\]") <?> + "math block" + +mathBlockWith start end = try $ do + start + spaces + result <- manyTill anyChar end + spaces + return $ BlockQuote [Para [TeX ("$" ++ result ++ "$")]] + +-- +-- list blocks +-- + +list = bulletList <|> orderedList <|> definitionList <?> "list" + +listItem = try $ do + ("item", _, args) <- command + spaces + state <- getState + let oldParserContext = stateParserContext state + updateState (\state -> state {stateParserContext = ListItemState}) + blocks <- many block + updateState (\state -> state {stateParserContext = oldParserContext}) + opt <- case args of + ([x]) | "[" `isPrefixOf` x && "]" `isSuffixOf` x -> + parseFromString (many inline) $ tail $ init x + _ -> return [] + return (opt, blocks) + +orderedList = try $ do + string "\\begin{enumerate}" + (_, style, delim) <- option (1, DefaultStyle, DefaultDelim) $ + try $ do failIfStrict + char '[' + res <- anyOrderedListMarker + char ']' + return res + spaces + option "" $ try $ do string "\\setlength{\\itemindent}" + char '{' + manyTill anyChar (char '}') + spaces + start <- option 1 $ try $ do failIfStrict + string "\\setcounter{enum" + many1 (oneOf "iv") + string "}{" + num <- many1 digit + char '}' + spaces + return $ (read num) + 1 + items <- many listItem + end "enumerate" + spaces + return $ OrderedList (start, style, delim) $ map snd items + +bulletList = try $ do + begin "itemize" + spaces + items <- many listItem + end "itemize" + spaces + return (BulletList $ map snd items) + +definitionList = try $ do + begin "description" + spaces + items <- many listItem + end "description" + spaces + return (DefinitionList items) + +-- +-- paragraph block +-- + +para = many1 inline >>~ spaces >>= return . Para . normalizeSpaces + +-- +-- title authors date +-- + +bibliographic = choice [ maketitle, title, authors, date ] + +maketitle = try (string "\\maketitle") >> spaces >> return Null + +title = try $ do + string "\\title{" + tit <- manyTill inline (char '}') + spaces + updateState (\state -> state { stateTitle = tit }) + return Null + +authors = try $ do + string "\\author{" + authors <- manyTill anyChar (char '}') + spaces + let authors' = map removeLeadingTrailingSpace $ lines $ + substitute "\\\\" "\n" authors + updateState (\state -> state { stateAuthors = authors' }) + return Null + +date = try $ do + string "\\date{" + date' <- manyTill anyChar (char '}') + spaces + updateState (\state -> state { stateDate = date' }) + return Null + +-- +-- item block +-- for use in unknown environments that aren't being parsed as raw latex +-- + +-- this forces items to be parsed in different blocks +itemBlock = try $ do + ("item", _, args) <- command + state <- getState + if (stateParserContext state == ListItemState) + then fail "item should be handled by list block" + else if null args + then return Null + else return $ Plain [Str (stripFirstAndLast (head args))] + +-- +-- raw LaTeX +-- + +specialEnvironment = do -- these are always parsed as raw + lookAhead (choice (map (\name -> begin name) ["tabular", "figure", + "tabbing", "eqnarry", "picture", "table", "verse", "theorem"])) + rawLaTeXEnvironment + +-- | Parse any LaTeX environment and return a Para block containing +-- the whole literal environment as raw TeX. +rawLaTeXEnvironment :: GenParser Char st Block +rawLaTeXEnvironment = try $ do + string "\\begin{" + name <- many1 letter + star <- option "" (string "*") -- for starred variants + let name' = name ++ star + char '}' + args <- option [] commandArgs + let argStr = concat args + contents <- manyTill (choice [ (many1 (noneOf "\\")), + (do + (Para [TeX str]) <- rawLaTeXEnvironment + return str), + string "\\" ]) + (end name') + spaces + return $ Para [TeX $ "\\begin{" ++ name' ++ "}" ++ argStr ++ + concat contents ++ "\\end{" ++ name' ++ "}"] + +unknownEnvironment = try $ do + state <- getState + result <- if stateParseRaw state -- check whether we should include raw TeX + then rawLaTeXEnvironment -- if so, get whole raw environment + else anyEnvironment -- otherwise just the contents + return result + +unknownCommand = try $ do + notFollowedBy' $ choice $ map end ["itemize", "enumerate", "description", + "document"] + (name, star, args) <- command + spaces + let argStr = concat args + state <- getState + if name == "item" && (stateParserContext state) == ListItemState + then fail "should not be parsed as raw" + else string "" + if stateParseRaw state + then return $ Plain [TeX ("\\" ++ name ++ star ++ argStr)] + else return $ Plain [Str (joinWithSep " " args)] + +-- latex comment +comment = try $ char '%' >> manyTill anyChar newline >> spaces >> return Null + +-- +-- inline +-- + +inline = choice [ str + , endline + , whitespace + , quoted + , apostrophe + , spacer + , strong + , math + , ellipses + , emDash + , enDash + , hyphen + , emph + , strikeout + , superscript + , subscript + , ref + , lab + , code + , url + , link + , image + , footnote + , linebreak + , accentedChar + , specialChar + , rawLaTeXInline + , escapedChar + , unescapedChar + ] <?> "inline" + +accentedChar = normalAccentedChar <|> specialAccentedChar + +normalAccentedChar = try $ do + char '\\' + accent <- oneOf "'`^\"~" + character <- (try $ char '{' >> letter >>~ char '}') <|> letter + let table = fromMaybe [] $ lookup character accentTable + let result = case lookup accent table of + Just num -> chr num + Nothing -> '?' + return $ Str [result] + +-- an association list of letters and association list of accents +-- and decimal character numbers. +accentTable = + [ ('A', [('`', 192), ('\'', 193), ('^', 194), ('~', 195), ('"', 196)]), + ('E', [('`', 200), ('\'', 201), ('^', 202), ('"', 203)]), + ('I', [('`', 204), ('\'', 205), ('^', 206), ('"', 207)]), + ('N', [('~', 209)]), + ('O', [('`', 210), ('\'', 211), ('^', 212), ('~', 213), ('"', 214)]), + ('U', [('`', 217), ('\'', 218), ('^', 219), ('"', 220)]), + ('a', [('`', 224), ('\'', 225), ('^', 227), ('"', 228)]), + ('e', [('`', 232), ('\'', 233), ('^', 234), ('"', 235)]), + ('i', [('`', 236), ('\'', 237), ('^', 238), ('"', 239)]), + ('n', [('~', 241)]), + ('o', [('`', 242), ('\'', 243), ('^', 244), ('~', 245), ('"', 246)]), + ('u', [('`', 249), ('\'', 250), ('^', 251), ('"', 252)]) ] + +specialAccentedChar = choice [ ccedil, aring, iuml, szlig, aelig, + oslash, pound, euro, copyright, sect ] + +ccedil = try $ do + char '\\' + letter <- oneOfStrings ["cc", "cC"] + let num = if letter == "cc" then 231 else 199 + return $ Str [chr num] + +aring = try $ do + char '\\' + letter <- oneOfStrings ["aa", "AA"] + let num = if letter == "aa" then 229 else 197 + return $ Str [chr num] + +iuml = try (string "\\\"") >> oneOfStrings ["\\i", "{\\i}"] >> + return (Str [chr 239]) + +icirc = try (string "\\^") >> oneOfStrings ["\\i", "{\\i}"] >> + return (Str [chr 238]) + +szlig = try (string "\\ss") >> return (Str [chr 223]) + +oslash = try $ do + char '\\' + letter <- choice [char 'o', char 'O'] + let num = if letter == 'o' then 248 else 216 + return $ Str [chr num] + +aelig = try $ do + char '\\' + letter <- oneOfStrings ["ae", "AE"] + let num = if letter == "ae" then 230 else 198 + return $ Str [chr num] + +pound = try (string "\\pounds") >> return (Str [chr 163]) + +euro = try (string "\\euro") >> return (Str [chr 8364]) + +copyright = try (string "\\copyright") >> return (Str [chr 169]) + +sect = try (string "\\S") >> return (Str [chr 167]) + +escapedChar = do + result <- escaped (oneOf " $%&_#{}\n") + return $ if result == Str "\n" then Str " " else result + +-- ignore standalone, nonescaped special characters +unescapedChar = oneOf "`$^&_#{}|<>" >> return (Str "") + +specialChar = choice [ backslash, tilde, caret, bar, lt, gt, doubleQuote ] + +backslash = try (string "\\textbackslash") >> return (Str "\\") + +tilde = try (string "\\ensuremath{\\sim}") >> return (Str "~") + +caret = try (string "\\^{}") >> return (Str "^") + +bar = try (string "\\textbar") >> return (Str "\\") + +lt = try (string "\\textless") >> return (Str "<") + +gt = try (string "\\textgreater") >> return (Str ">") + +doubleQuote = char '"' >> return (Str "\"") + +code = code1 <|> code2 + +code1 = try $ do + string "\\verb" + marker <- anyChar + result <- manyTill anyChar (char marker) + return $ Code $ removeLeadingTrailingSpace result + +code2 = try $ do + string "\\texttt{" + result <- manyTill (noneOf "\\\n~$%^&{}") (char '}') + return $ Code result + +emph = try $ oneOfStrings [ "\\emph{", "\\textit{" ] >> + manyTill inline (char '}') >>= return . Emph + +strikeout = try $ string "\\sout{" >> manyTill inline (char '}') >>= + return . Strikeout + +superscript = try $ string "\\textsuperscript{" >> + manyTill inline (char '}') >>= return . Superscript + +-- note: \textsubscript isn't a standard latex command, but we use +-- a defined version in pandoc. +subscript = try $ string "\\textsubscript{" >> manyTill inline (char '}') >>= + return . Subscript + +apostrophe = char '\'' >> return Apostrophe + +quoted = doubleQuoted <|> singleQuoted + +singleQuoted = enclosed singleQuoteStart singleQuoteEnd inline >>= + return . Quoted SingleQuote . normalizeSpaces + +doubleQuoted = enclosed doubleQuoteStart doubleQuoteEnd inline >>= + return . Quoted DoubleQuote . normalizeSpaces + +singleQuoteStart = char '`' + +singleQuoteEnd = try $ char '\'' >> notFollowedBy alphaNum + +doubleQuoteStart = string "``" + +doubleQuoteEnd = try $ string "''" + +ellipses = try $ string "\\ldots" >> optional (try (string "{}")) >> + return Ellipses + +enDash = try (string "--") >> return EnDash + +emDash = try (string "---") >> return EmDash + +hyphen = char '-' >> return (Str "-") + +lab = try $ do + string "\\label{" + result <- manyTill anyChar (char '}') + return $ Str $ "(" ++ result ++ ")" + +ref = try (string "\\ref{") >> manyTill anyChar (char '}') >>= return . Str + +strong = try (string "\\textbf{") >> manyTill inline (char '}') >>= + return . Strong + +whitespace = many1 (oneOf "~ \t") >> return Space + +-- hard line break +linebreak = try (string "\\\\") >> return LineBreak + +spacer = try (string "\\,") >> return (Str "") + +str = many1 (noneOf specialChars) >>= return . Str + +-- endline internal to paragraph +endline = try $ newline >> notFollowedBy blankline >> return Space + +-- math +math = math1 <|> math2 <?> "math" + +math1 = try $ do + char '$' + result <- many (noneOf "$") + char '$' + return $ TeX ("$" ++ result ++ "$") + +math2 = try $ do + string "\\(" + result <- many (noneOf "$") + string "\\)" + return $ TeX ("$" ++ result ++ "$") + +-- +-- links and images +-- + +url = try $ do + string "\\url" + url <- charsInBalanced '{' '}' + return $ Link [Code url] (url, "") + +link = try $ do + string "\\href{" + url <- manyTill anyChar (char '}') + char '{' + label <- manyTill inline (char '}') + return $ Link (normalizeSpaces label) (url, "") + +image = try $ do + ("includegraphics", _, args) <- command + let args' = filter isArg args -- filter out options + let src = if null args' then + ("", "") + else + (stripFirstAndLast (head args'), "") + return $ Image [Str "image"] src + +footnote = try $ do + (name, _, (contents:[])) <- command + if ((name == "footnote") || (name == "thanks")) + then string "" + else fail "not a footnote or thanks command" + let contents' = stripFirstAndLast contents + -- parse the extracted block, which may contain various block elements: + rest <- getInput + setInput $ contents' + blocks <- parseBlocks + setInput rest + return $ Note blocks + +-- | Parse any LaTeX command and return it in a raw TeX inline element. +rawLaTeXInline :: GenParser Char ParserState Inline +rawLaTeXInline = try $ do + (name, star, args) <- command + state <- getState + if ((name == "begin") || (name == "end") || (name == "item")) + then fail "not an inline command" + else string "" + return $ TeX ("\\" ++ name ++ star ++ concat args) + |