aboutsummaryrefslogtreecommitdiff
path: root/src/Text/Pandoc/Writers/LaTeX.hs
blob: f64e06e243aca3f554e0c39bb4f55dd0eee23762 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
{-
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.Writers.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 'Pandoc' format into LaTeX.
-}
module Text.Pandoc.Writers.LaTeX ( writeLaTeX ) where
import Text.Pandoc.Definition
import Text.Pandoc.Shared
import Text.Printf ( printf )
import Data.List ( (\\), isInfixOf, isSuffixOf, intersperse )
import Data.Char ( toLower )
import qualified Data.Set as S
import Control.Monad.State
import Text.PrettyPrint.HughesPJ hiding ( Str )

data WriterState = 
  WriterState { stIncludes :: S.Set String -- strings to include in header
              , stInNote   :: Bool         -- @True@ if we're in a note
              , stOLLevel  :: Int }        -- level of ordered list nesting 

-- | Add line to header.
addToHeader :: String -> State WriterState ()
addToHeader str = do
  st <- get
  let includes = stIncludes st
  put st {stIncludes = S.insert str includes}

-- | Convert Pandoc to LaTeX.
writeLaTeX :: WriterOptions -> Pandoc -> String
writeLaTeX options document = 
  render $ evalState (pandocToLaTeX options document) $ 
  WriterState { stIncludes = S.empty, stInNote = False, stOLLevel = 1 } 

pandocToLaTeX :: WriterOptions -> Pandoc -> State WriterState Doc
pandocToLaTeX options (Pandoc meta blocks) = do
  main     <- blockListToLaTeX blocks
  head     <- if writerStandalone options
                 then latexHeader options meta
                 else return empty
  let before = if null (writerIncludeBefore options)
                  then empty
                  else text (writerIncludeBefore options)
  let after  = if null (writerIncludeAfter options)
                  then empty
                  else text (writerIncludeAfter options)
  let body = before $$ main $$ after
  let toc  =  if writerTableOfContents options
                 then text "\\tableofcontents\n"
                 else empty 
  let foot = if writerStandalone options
                then text "\\end{document}"
                else empty 
  return $ head $$ toc $$ body $$ foot

-- | Insert bibliographic information into LaTeX header.
latexHeader :: WriterOptions -- ^ Options, including LaTeX header
            -> Meta          -- ^ Meta with bibliographic information
            -> State WriterState Doc
latexHeader options (Meta title authors date) = do
  titletext <- if null title
                  then return empty
                  else inlineListToLaTeX title >>= return . inCmd "title"
  headerIncludes <- get >>= return . S.toList . stIncludes
  let extras = text $ unlines headerIncludes
  let verbatim  = if "\\usepackage{fancyvrb}" `elem` headerIncludes
                     then text "\\VerbatimFootnotes % allows verbatim text in footnotes"
                     else empty
  let authorstext = text $ "\\author{" ++ 
                    joinWithSep "\\\\" (map stringToLaTeX authors) ++ "}"
  let datetext  = if date == ""
                     then empty 
                     else text $ "\\date{" ++ stringToLaTeX date ++ "}"
  let maketitle = if null title then empty else text "\\maketitle"
  let secnumline = if (writerNumberSections options)
                      then empty 
                      else text "\\setcounter{secnumdepth}{0}"
  let baseHeader = text $ writerHeader options
  let header     = baseHeader $$ extras
  return $ header $$ secnumline $$ verbatim $$ titletext $$ authorstext $$
           datetext $$ text "\\begin{document}" $$ maketitle $$ text ""

-- escape things as needed for LaTeX

stringToLaTeX :: String -> String
stringToLaTeX = escapeStringUsing latexEscapes
  where latexEscapes = backslashEscapes "{}$%&_#" ++ 
                       [ ('^', "\\^{}")
                       , ('\\', "\\textbackslash{}")
                       , ('~', "\\ensuremath{\\sim}")
                       , ('|', "\\textbar{}")
                       , ('<', "\\textless{}")
                       , ('>', "\\textgreater{}")
                       ]

-- | Puts contents into LaTeX command.
inCmd :: String -> Doc -> Doc
inCmd cmd contents = char '\\' <> text cmd <> braces contents

-- | Remove all code elements from list of inline elements
-- (because it's illegal to have verbatim inside some command arguments)
deVerb :: [Inline] -> [Inline]
deVerb [] = []
deVerb ((Code str):rest) = 
  (TeX $ "\\texttt{" ++ stringToLaTeX str ++ "}"):(deVerb rest)
deVerb (other:rest) = other:(deVerb rest)

-- | Convert Pandoc block element to LaTeX.
blockToLaTeX :: Block     -- ^ Block to convert
             -> State WriterState Doc
blockToLaTeX Null = return empty
blockToLaTeX (Plain lst) = wrapped inlineListToLaTeX lst >>= return 
blockToLaTeX (Para lst) = 
  wrapped inlineListToLaTeX lst >>= return . (<> char '\n')
blockToLaTeX (BlockQuote lst) = do
  contents <- blockListToLaTeX lst
  return $ text "\\begin{quote}" $$ contents $$ text "\\end{quote}"
blockToLaTeX (CodeBlock str) = do
  st <- get
  env <- if stInNote st
            then do addToHeader "\\usepackage{fancyvrb}"
                    return "Verbatim"
            else return "verbatim"
  return $ text ("\\begin{" ++ env ++ "}\n") <> text str <> 
           text ("\n\\end{" ++ env ++ "}")
blockToLaTeX (RawHtml str) = return empty
blockToLaTeX (BulletList lst) = do
  items <- mapM listItemToLaTeX lst
  return $ text "\\begin{itemize}" $$ vcat items $$ text "\\end{itemize}"
blockToLaTeX (OrderedList (start, numstyle, numdelim) lst) = do
  st <- get
  let oldlevel = stOLLevel st
  put $ st {stOLLevel = oldlevel + 1}
  items <- mapM listItemToLaTeX lst
  modify (\st -> st {stOLLevel = oldlevel})
  exemplar <- if numstyle /= DefaultStyle || numdelim /= DefaultDelim
                 then do addToHeader "\\usepackage{enumerate}"
                         return $ char '[' <> 
                                  text (head (orderedListMarkers (1, numstyle,
                                  numdelim))) <> char ']'
                 else return empty
  let resetcounter = if start /= 1 && oldlevel <= 4
                        then text $ "\\setcounter{enum" ++ 
                             map toLower (toRomanNumeral oldlevel) ++
                             "}{" ++ show (start - 1) ++ "}"
                        else empty 
  return $ text "\\begin{enumerate}" <> exemplar $$ resetcounter $$
           vcat items $$ text "\\end{enumerate}"
blockToLaTeX (DefinitionList lst) = do
  items <- mapM defListItemToLaTeX lst
  return $ text "\\begin{description}" $$ vcat items $$
           text "\\end{description}"
blockToLaTeX HorizontalRule = return $ text $
    "\\begin{center}\\rule{3in}{0.4pt}\\end{center}\n"
blockToLaTeX (Header level lst) = do
  txt <- inlineListToLaTeX (deVerb lst)
  return $ if (level > 0) && (level <= 3)
              then text ("\\" ++ (concat (replicate (level - 1) "sub")) ++ 
                   "section{") <> txt <> text "}\n"
              else txt <> char '\n'
blockToLaTeX (Table caption aligns widths heads rows) = do
  headers <- tableRowToLaTeX heads
  captionText <- inlineListToLaTeX caption
  rows' <- mapM tableRowToLaTeX rows
  let colWidths = map (printf "%.2f") widths
  let colDescriptors = concat $ zipWith
                                (\width align -> ">{\\PBS" ++ 
                                (case align of 
                                       AlignLeft -> "\\raggedright"
                                       AlignRight -> "\\raggedleft"
                                       AlignCenter -> "\\centering"
                                       AlignDefault -> "\\raggedright") ++
                                "\\hspace{0pt}}p{" ++ width ++ 
                                "\\columnwidth}")
                                colWidths aligns
  let tableBody = text ("\\begin{tabular}{" ++ colDescriptors ++ "}") $$
                  headers $$ text "\\hline" $$ vcat rows' $$ 
                  text "\\end{tabular}" 
  let centered txt = text "\\begin{center}" $$ txt $$ text "\\end{center}"
  addToHeader "\\usepackage{array}\n\
    \% This is needed because raggedright in table elements redefines \\\\:\n\
    \\\newcommand{\\PreserveBackslash}[1]{\\let\\temp=\\\\#1\\let\\\\=\\temp}\n\
    \\\let\\PBS=\\PreserveBackslash"
  return $ if isEmpty captionText
              then centered tableBody <> char '\n'
              else text "\\begin{table}[h]" $$ centered tableBody $$ 
                   inCmd "caption" captionText $$ text "\\end{table}\n" 

blockListToLaTeX lst = mapM blockToLaTeX lst >>= return . vcat

tableRowToLaTeX cols = mapM blockListToLaTeX cols >>= 
  return . ($$ text "\\\\") . foldl (\row item -> row $$
  (if isEmpty row then empty else text " & ") <> item) empty

listItemToLaTeX lst = blockListToLaTeX lst >>= return .  (text "\\item " $$) .
                      (nest 2)

defListItemToLaTeX (term, def) = do
    term' <- inlineListToLaTeX $ deVerb term
    def'  <- blockListToLaTeX def
    return $ text "\\item[" <> term' <> text "]" $$ def'

-- | Convert list of inline elements to LaTeX.
inlineListToLaTeX :: [Inline]  -- ^ Inlines to convert
                  -> State WriterState Doc
inlineListToLaTeX lst = mapM inlineToLaTeX lst >>= return . hcat

isQuoted :: Inline -> Bool
isQuoted (Quoted _ _) = True
isQuoted Apostrophe = True
isQuoted _ = False

-- | Convert inline element to LaTeX
inlineToLaTeX :: Inline    -- ^ Inline to convert
              -> State WriterState Doc
inlineToLaTeX (Emph lst) =
  inlineListToLaTeX (deVerb lst) >>= return . inCmd "emph"
inlineToLaTeX (Strong lst) = 
  inlineListToLaTeX (deVerb lst) >>= return . inCmd "textbf" 
inlineToLaTeX (Strikeout lst) = do
  contents <- inlineListToLaTeX $ deVerb lst
  addToHeader "\\usepackage[normalem]{ulem}"
  return $ inCmd "sout" contents
inlineToLaTeX (Superscript lst) = 
  inlineListToLaTeX (deVerb lst) >>= return . inCmd "textsuperscript"
inlineToLaTeX (Subscript lst) = do
  contents <- inlineListToLaTeX $ deVerb lst
  -- oddly, latex includes \textsuperscript but not \textsubscript
  -- so we have to define it:
  addToHeader "\\newcommand{\\textsubscript}[1]{\\ensuremath{_{\\scriptsize\\textrm{#1}}}}"
  return $ inCmd "textsubscript" contents
inlineToLaTeX (Code str) = do
  st <- get
  if stInNote st
     then do addToHeader "\\usepackage{fancyvrb}"
     else return ()
  let chr = ((enumFromTo '!' '~') \\ str) !! 0
  return $ text $ "\\verb" ++ [chr] ++ str ++ [chr]
inlineToLaTeX (Quoted SingleQuote lst) = do
  contents <- inlineListToLaTeX lst
  let s1 = if (not (null lst)) && (isQuoted (head lst))
              then text "\\,"
              else empty 
  let s2 = if (not (null lst)) && (isQuoted (last lst))
              then text "\\,"
              else empty
  return $ char '`' <> s1 <> contents <> s2 <> char '\''
inlineToLaTeX (Quoted DoubleQuote lst) = do
  contents <- inlineListToLaTeX lst
  let s1 = if (not (null lst)) && (isQuoted (head lst))
              then text "\\,"
              else empty 
  let s2 = if (not (null lst)) && (isQuoted (last lst))
              then text "\\,"
              else empty
  return $ text "``" <> s1 <> contents <> s2 <> text "''"
inlineToLaTeX Apostrophe = return $ char '\''
inlineToLaTeX EmDash = return $ text "---"
inlineToLaTeX EnDash = return $ text "--"
inlineToLaTeX Ellipses = return $ text "\\ldots{}"
inlineToLaTeX (Str str) = return $ text $ stringToLaTeX str
inlineToLaTeX (TeX str) = return $ text str
inlineToLaTeX (HtmlInline str) = return empty
inlineToLaTeX (LineBreak) = return $ text "\\\\" 
inlineToLaTeX Space = return $ char ' '
inlineToLaTeX (Link txt (src, _)) = do
  addToHeader "\\usepackage[breaklinks=true]{hyperref}"
  case txt of
        [Code x] | x == src ->  -- autolink
             do addToHeader "\\usepackage{url}" 
                return $ text $ "\\url{" ++ x ++ "}"
        _ -> do contents <- inlineListToLaTeX $ deVerb txt
                return $ text ("\\href{" ++ src ++ "}{") <> contents <> 
                         char '}'
inlineToLaTeX (Image alternate (source, tit)) = do
  addToHeader "\\usepackage{graphicx}"
  return $ text $ "\\includegraphics{" ++ source ++ "}" 
inlineToLaTeX (Note contents) = do
  st <- get
  put (st {stInNote = True})
  contents' <- blockListToLaTeX contents
  modify (\st -> st {stInNote = False})
  let rawnote = stripTrailingNewlines $ render contents'
  -- note: a \n before } is needed when note ends with a Verbatim environment
  let optNewline = "\\end{Verbatim}" `isSuffixOf` rawnote
  return $ text "%\n\\footnote{" <> 
           text rawnote <> (if optNewline then char '\n' else empty) <> char '}'