pandoc/src/Text/Pandoc/Readers/LaTeX.hs
fiddlosopher 48b8267126 Fixed a serious bug in the Markdown reader (also affecting LaTeX
and RST readers).  The problem:  these readers ran 'runParser' on
processed chunks of text to handle embedded block lists in lists
and quotation blocks.  But then any changes made to the parser state
in these chunks was lost, as the state is local to the parser.
So, for example, footnotes didn't work in quotes or list items.

The fix:  instead of calling runParser on some raw text, use
setInput to make it the input, then parse it, then use setInput
to restore the input to what it was before.  This is shorter and more
elegant, and it fixes the problem.

'BlockQuoteContext' was also eliminated from ParserContext, as it
isn't used anywhere.


git-svn-id: https://pandoc.googlecode.com/svn/trunk@261 788f1e2b-df1e-0410-8736-df70ead52e1b
2006-12-21 09:02:06 +00:00

626 lines
16 KiB
Haskell

{-
Copyright (C) 2006 John MacFarlane <jgm at berkeley dot 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 John MacFarlane
License : GNU GPL, version 2 or above
Maintainer : John MacFarlane <jgm at berkeley dot 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.ParserCombinators.Pandoc
import Text.Pandoc.Definition
import Text.Pandoc.Shared
import Maybe ( fromMaybe )
import Char ( chr )
-- | Parse LaTeX from string and return 'Pandoc' document.
readLaTeX :: ParserState -- ^ Parser state, including options for parser
-> String -- ^ String to parse
-> Pandoc
readLaTeX = readWith parseLaTeX
-- for testing
testString = testStringWith parseLaTeX
-- characters with special meaning
specialChars = "\\$%&^&_~#{}\n \t|<>"
--
-- utility functions
--
-- | Change quotation marks in a string back to "basic" quotes.
normalizeQuotes :: String -> String
normalizeQuotes = gsub "''" "\"" . gsub "`" "'"
-- | Change LaTeX En dashes between digits to hyphens.
normalizeDashes :: String -> String
normalizeDashes = gsub "([0-9])--([0-9])" "\\1-\\2"
normalizePunctuation :: String -> String
normalizePunctuation = normalizeDashes . normalizeQuotes
-- | Returns text between brackets and its matching pair.
bracketedText openB closeB = try (do
char openB
result <- many (choice [ oneOfStrings [ ['\\', openB], ['\\', closeB] ],
count 1 (noneOf [openB, closeB]),
bracketedText openB closeB ])
char closeB
return ([openB] ++ (concat result) ++ [closeB]))
-- | Returns an option or argument of a LaTeX command.
optOrArg = choice [ (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 = try (do
char '\\'
name <- many1 alphaNum
star <- option "" (string "*") -- some commands have starred versions
args <- commandArgs
return (name, star, args))
begin name = try (do
string "\\begin{"
string name
char '}'
option [] commandArgs
spaces
return name)
end name = try (do
string "\\end{"
string name
char '}'
spaces
return name)
-- | Returns a list of block elements containing the contents of an
-- environment.
environment name = try (do
begin name
spaces
contents <- manyTill block (end name)
return contents)
anyEnvironment = try (do
string "\\begin{"
name <- many alphaNum
star <- option "" (string "*") -- some environments have starred variants
char '}'
option [] commandArgs
spaces
contents <- manyTill block (end (name ++ star))
return (BlockQuote contents))
--
-- parsing documents
--
-- | Process LaTeX preamble, extracting metadata.
processLaTeXPreamble = do
manyTill (choice [bibliographic, comment, unknownCommand, nullBlock])
(try (string "\\begin{document}"))
spaces
-- | Parse LaTeX and return 'Pandoc'.
parseLaTeX = do
option () processLaTeXPreamble -- preamble might not be present (fragment)
blocks <- parseBlocks
spaces
option "" (string "\\end{document}") -- might not be present (in fragment)
spaces
eof
state <- getState
let keyBlocks = stateKeyBlocks state
let noteBlocks = stateNoteBlocks state
let blocks' = filter (/= Null) blocks
let title' = stateTitle state
let authors' = stateAuthors state
let date' = stateDate state
return (Pandoc (Meta title' authors' date')
(blocks' ++ (reverse noteBlocks) ++ (reverse keyBlocks)))
--
-- parsing blocks
--
parseBlocks = do
spaces
result <- many block
return result
block = choice [ hrule, codeBlock, header, list, blockQuote, mathBlock,
comment, bibliographic, para, specialEnvironment,
itemBlock, unknownEnvironment, unknownCommand ] <?>
"block"
--
-- header blocks
--
header = choice (map headerLevel (enumFromTo 1 5)) <?> "header"
headerLevel n = try (do
let subs = concat $ replicate (n - 1) "sub"
string ("\\" ++ subs ++ "section")
option ' ' (char '*')
char '{'
title <- manyTill inline (char '}')
spaces
return (Header n (normalizeSpaces title)))
--
-- hrule block
--
hrule = try (do
oneOfStrings [ "\\begin{center}\\rule{3in}{0.4pt}\\end{center}\n\n",
"\\newpage" ]
spaces
return HorizontalRule)
--
-- code blocks
--
codeBlock = try (do
string "\\begin{verbatim}" -- don't use begin function because it
-- gobbles whitespace
option "" blanklines -- we want to gobble blank lines, but not
-- leading space
contents <- manyTill anyChar (try (string "\\end{verbatim}"))
spaces
return (CodeBlock (stripTrailingNewlines contents)))
--
-- block quotes
--
blockQuote = choice [ blockQuote1, blockQuote2 ] <?> "blockquote"
blockQuote1 = try (do
blocks <- environment "quote"
spaces
return (BlockQuote blocks))
blockQuote2 = try (do
blocks <- environment "quotation"
spaces
return (BlockQuote blocks))
--
-- math block
--
mathBlock = mathBlockWith (begin "equation") (end "equation") <|>
mathBlockWith (begin "displaymath") (end "displaymath") <|>
mathBlockWith (string "\\[") (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 <?> "list"
listItem = try (do
("item", _, _) <- command
spaces
state <- getState
let oldParserContext = stateParserContext state
updateState (\state -> state {stateParserContext = ListItemState})
blocks <- many block
updateState (\state -> state {stateParserContext = oldParserContext})
return blocks)
orderedList = try (do
begin "enumerate"
spaces
items <- many listItem
end "enumerate"
spaces
return (OrderedList items))
bulletList = try (do
begin "itemize"
spaces
items <- many listItem
end "itemize"
spaces
return (BulletList items))
--
-- paragraph block
--
para = try (do
result <- many1 inline
spaces
return (Para (normalizeSpaces result)))
--
-- title authors date
--
bibliographic = choice [ maketitle, title, authors, date ]
maketitle = try (do
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 $
gsub "\\\\\\\\" "\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
followedBy' (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"
char '{'
name <- many1 alphaNum
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' (string "\\end{itemize}")
notFollowedBy' (string "\\end{enumerate}")
notFollowedBy' (string "\\end{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 (do
char '%'
result <- manyTill anyChar newline
spaces
return Null)
--
-- inline
--
inline = choice [ strong, emph, ref, lab, code, linebreak, math, ldots,
accentedChar, specialChar, specialInline, escapedChar,
unescapedChar, str, endline, whitespace ] <?> "inline"
specialInline = choice [ link, image, footnote, rawLaTeXInline ] <?>
"link, raw TeX, note, or image"
ldots = try (do
string "\\ldots"
return (Str "..."))
accentedChar = normalAccentedChar <|> specialAccentedChar
normalAccentedChar = try (do
char '\\'
accent <- oneOf "'`^\"~"
character <- choice [ between (char '{') (char '}') anyChar, anyChar ]
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 <- choice [try (string "cc"), try (string "cC")]
let num = if letter == "cc" then 231 else 199
return (Str [chr num]))
aring = try (do
char '\\'
letter <- choice [try (string "aa"), try (string "AA")]
let num = if letter == "aa" then 229 else 197
return (Str [chr num]))
iuml = try (do
string "\\\""
choice [try (string "\\i"), try (string "{\\i}")]
return (Str [chr 239]))
icirc = try (do
string "\\^"
choice [try (string "\\i"), try (string "{\\i}")]
return (Str [chr 238]))
szlig = try (do
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 <- choice [try (string "ae"), try (string "AE")]
let num = if letter == "ae" then 230 else 198
return (Str [chr num]))
pound = try (do
string "\\pounds"
return (Str [chr 163]))
euro = try (do
string "\\euro"
return (Str [chr 8364]))
copyright = try (do
string "\\copyright"
return (Str [chr 169]))
sect = try (do
string "\\S"
return (Str [chr 167]))
escapedChar = do
result <- escaped (oneOf " $%^&_#{}\n")
return (if result == Str "\n" then Str " " else result)
unescapedChar = do -- ignore standalone, nonescaped special characters
oneOf "$^&_#{}|<>"
return (Str "")
specialChar = choice [ backslash, bar, lt, gt ]
backslash = try (do
string "\\textbackslash"
return (Str "\\"))
bar = try (do
string "\\textbar"
return (Str "\\"))
lt = try (do
string "\\textless"
return (Str "<"))
gt = try (do
string "\\textgreater"
return (Str ">"))
code = try (do
string "\\verb"
marker <- anyChar
result <- manyTill anyChar (char marker)
let result' = removeLeadingTrailingSpace result
return (Code result'))
emph = try (do
oneOfStrings [ "\\emph{", "\\textit{" ]
result <- manyTill inline (char '}')
return (Emph result))
lab = try (do
string "\\label{"
result <- manyTill anyChar (char '}')
return (Str ("(" ++ result ++ ")")))
ref = try (do
string "\\ref{"
result <- manyTill anyChar (char '}')
return (Str (result)))
strong = try (do
string "\\textbf{"
result <- manyTill inline (char '}')
return (Strong result))
whitespace = do
many1 (oneOf "~ \t")
return Space
-- hard line break
linebreak = try (do
string "\\\\"
return LineBreak)
str = do
result <- many1 (noneOf specialChars)
return (Str (normalizePunctuation result))
-- endline internal to paragraph
endline = try (do
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
--
link = try (do
string "\\href{"
url <- manyTill anyChar (char '}')
char '{'
label <- manyTill inline (char '}')
return (Link (normalizeSpaces label) (Src url "")))
image = try (do
("includegraphics", _, args) <- command
let args' = filter isArg args -- filter out options
let src = if null args' then
Src "" ""
else
Src (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
state <- getState
let notes = stateNoteBlocks state
let nextRef = case notes of
[] -> "1"
(Note ref body):rest -> (show ((read ref) + 1))
setState (state { stateNoteBlocks = (Note nextRef blocks):notes })
return (NoteRef nextRef))
-- | 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
let argStr = concat args
state <- getState
if ((name == "begin") || (name == "end") || (name == "item"))
then fail "not an inline command"
else string ""
return (TeX ("\\" ++ name ++ star ++ argStr)))