+ Added support for superscript, subscript, and

  strikeout to all writers. (Thanks to Bradley Kuhn
  for the patches for strikeout, here slightly modified.)
+ Refactored character escaping using the new functions
  escapeStringUsing and backslashEscapes.
+ Added state to LaTeX writer, which now keeps track of what
  packages need to be included in the preamble, based on the
  content of the document. (Thus, e.g., ulem is only required
  if you use strikeout.)


git-svn-id: https://pandoc.googlecode.com/svn/trunk@755 788f1e2b-df1e-0410-8736-df70ead52e1b

1 files changed, 177 insertions, 132 deletions

diff --git a/src/Text/Pandoc/Writers/LaTeX.hs b/src/Text/Pandoc/Writers/LaTeX.hs
index e0c80d24e..f0bb92002 100644
--- a/src/Text/Pandoc/Writers/LaTeX.hs
+++ b/src/Text/Pandoc/Writers/LaTeX.hs
@@ -34,143 +34,164 @@ import Text.Pandoc.Definition
 import Text.Pandoc.Shared
 import Text.Printf ( printf )
 import Data.List ( (\\) )
+import qualified Data.Set as S
+import Control.Monad.State
+
+type WriterState = S.Set String  -- set of strings to include in header
+                                 -- constructed based on content of document
+
+-- | Add line to header.
+addToHeader :: String -> State WriterState ()
+addToHeader str = modify (S.insert str)
 
 -- | Convert Pandoc to LaTeX.
 writeLaTeX :: WriterOptions -> Pandoc -> String
-writeLaTeX options (Pandoc meta blocks) = 
-  let body = (writerIncludeBefore options) ++ 
-             (concatMap blockToLaTeX blocks) ++
-             (writerIncludeAfter options)
-      head = if writerStandalone options
-                then latexHeader options meta
-                else ""
-      toc  = if writerTableOfContents options
-                then "\\tableofcontents\n\n"
-                else "" 
-      foot = if writerStandalone options
+writeLaTeX options document = 
+  evalState (pandocToLaTeX options document) S.empty 
+
+pandocToLaTeX :: WriterOptions -> Pandoc -> State WriterState String
+pandocToLaTeX options (Pandoc meta blocks) = do
+  main     <- blockListToLaTeX blocks
+  head     <- if writerStandalone options
+                 then latexHeader options meta
+                 else return ""
+  let body =  writerIncludeBefore options ++ main ++
+              writerIncludeAfter options
+  let toc  =  if writerTableOfContents options
+                 then "\\tableofcontents\n\n"
+                 else "" 
+  let foot = if writerStandalone options
                 then "\n\\end{document}\n"
                 else ""
-  in  head ++ toc ++ body ++ foot
+  return $ head ++ toc ++ body ++ foot
 
 -- | Insert bibliographic information into LaTeX header.
 latexHeader :: WriterOptions -- ^ Options, including LaTeX header
             -> Meta          -- ^ Meta with bibliographic information
-            -> String
-latexHeader options (Meta title authors date) =
-  let titletext = if null title
-                     then "" 
-                     else "\\title{" ++ inlineListToLaTeX title ++ "}\n"
-      authorstext = if null authors
+            -> State WriterState String
+latexHeader options (Meta title authors date) = do
+  titletext    <- if null title
+                     then return "" 
+                     else do title' <- inlineListToLaTeX title
+                             return $ "\\title{" ++ title' ++ "}\n"
+  extras       <- get
+  let authorstext = if null authors
                        then "" 
                        else "\\author{" ++ (joinWithSep "\\\\" 
                             (map stringToLaTeX authors)) ++ "}\n"
-      datetext = if date == ""
-                    then "" 
-                    else "\\date{" ++ stringToLaTeX date ++ "}\n"
-      maketitle = if null title then "" else "\\maketitle\n\n" 
-      secnumline = if (writerNumberSections options)
+  let datetext  = if date == ""
+                     then "" 
+                     else "\\date{" ++ stringToLaTeX date ++ "}\n"
+  let maketitle = if null title then "" else "\\maketitle\n\n" 
+  let secnumline = if (writerNumberSections options)
                       then "" 
                       else "\\setcounter{secnumdepth}{0}\n" 
-      header     = writerHeader options in
-  header ++ secnumline ++ titletext ++ authorstext ++ datetext ++ 
-  "\\begin{document}\n" ++ maketitle
+  let baseHeader = writerHeader options
+  let header     = baseHeader ++ (unlines $ S.toList extras)
+  return $ header ++ secnumline ++ titletext ++ authorstext ++ datetext ++ 
+           "\\begin{document}\n" ++ maketitle
 
 -- escape things as needed for LaTeX
 
-escapeCharForLaTeX :: Char -> String
-escapeCharForLaTeX ch =
-  case ch of
-       '\\' -> "\\textbackslash{}"
-       '{'  -> "\\{"
-       '}'  -> "\\}"
-       '$'  -> "\\$"
-       '%'  -> "\\%"
-       '&'  -> "\\&"
-       '~'  -> "\\~"
-       '_'  -> "\\_"
-       '#'  -> "\\#"
-       '^'  -> "\\^{}"
-       '|'  -> "\\textbar{}"
-       '<'  -> "\\textless{}"
-       '>'  -> "\\textgreater{}"
-       x    -> [x]
-
--- | Escape string for LaTeX
 stringToLaTeX :: String -> String
-stringToLaTeX = concatMap escapeCharForLaTeX
+stringToLaTeX = escapeStringUsing latexEscapes
+  where latexEscapes = [
+          ('\\', "\\textbackslash{}"),
+          ('{', "\\{"),
+          ('}', "\\}"),
+          ('$', "\\$"),
+          ('%', "\\%"),
+          ('&', "\\&"),
+          ('~', "\\~"),
+          ('_', "\\_"),
+          ('#', "\\#"),
+          ('^', "\\^{}"),
+          ('|', "\\textbar{}"),
+          ('<', "\\textless{}"),
+          ('>', "\\textgreater{}")
+          ]
 
 -- | Remove all code elements from list of inline elements
 -- (because it's illegal to have a \\verb inside a command argument)
 deVerb :: [Inline] -> [Inline]
 deVerb [] = []
-deVerb ((Code str):rest) = (Str str):(deVerb rest)
+deVerb ((Code str):rest) = 
+  (Str $ "\\texttt{" ++ stringToLaTeX str ++ "}"):(deVerb rest)
 deVerb (other:rest) = other:(deVerb rest)
 
 -- | Convert Pandoc block element to LaTeX.
 blockToLaTeX :: Block     -- ^ Block to convert
-             -> String 
-blockToLaTeX Null = ""
-blockToLaTeX (Plain lst) = inlineListToLaTeX lst ++ "\n"
-blockToLaTeX (Para lst) = (inlineListToLaTeX lst) ++ "\n\n"
-blockToLaTeX (BlockQuote lst) = "\\begin{quote}\n" ++ 
-    (concatMap blockToLaTeX lst) ++ "\\end{quote}\n"
-blockToLaTeX (CodeBlock str) = "\\begin{verbatim}\n" ++ str ++ 
-    "\n\\end{verbatim}\n"
-blockToLaTeX (RawHtml str) = ""
-blockToLaTeX (BulletList lst) = "\\begin{itemize}\n" ++ 
-    (concatMap listItemToLaTeX lst) ++ "\\end{itemize}\n"
-blockToLaTeX (OrderedList lst) = "\\begin{enumerate}\n" ++ 
-    (concatMap listItemToLaTeX lst) ++ "\\end{enumerate}\n"
-blockToLaTeX (DefinitionList lst) = 
-    let defListItemToLaTeX (term, def) = "\\item[" ++ 
-           substitute "]" "\\]" (inlineListToLaTeX term) ++ "] " ++
-           concatMap blockToLaTeX def
-    in  "\\begin{description}\n" ++ concatMap defListItemToLaTeX lst ++ 
-        "\\end{description}\n"
-blockToLaTeX HorizontalRule = 
+             -> State WriterState String 
+blockToLaTeX Null = return ""
+blockToLaTeX (Plain lst) = (inlineListToLaTeX lst) >>= (return . (++ "\n"))
+blockToLaTeX (Para lst) = (inlineListToLaTeX lst) >>= (return . (++ "\n\n"))
+blockToLaTeX (BlockQuote lst) = do
+  contents <- blockListToLaTeX lst
+  return $ "\\begin{quote}\n" ++ contents ++ "\\end{quote}\n"
+blockToLaTeX (CodeBlock str) = return $ 
+  "\\begin{verbatim}\n" ++ str ++ "\n\\end{verbatim}\n"
+blockToLaTeX (RawHtml str) = return ""
+blockToLaTeX (BulletList lst) = do
+  items <- mapM listItemToLaTeX lst
+  return $ "\\begin{itemize}\n" ++ concat items ++ "\\end{itemize}\n"
+blockToLaTeX (OrderedList lst) = do
+  items <- mapM listItemToLaTeX lst
+  return $ "\\begin{enumerate}\n" ++ concat items ++ "\\end{enumerate}\n"
+blockToLaTeX (DefinitionList lst) = do
+  items <- mapM defListItemToLaTeX lst
+  return $ "\\begin{description}\n" ++ concat items ++ "\\end{description}\n"
+blockToLaTeX HorizontalRule = return $
     "\\begin{center}\\rule{3in}{0.4pt}\\end{center}\n\n"
-blockToLaTeX (Header level lst) = 
-    if (level > 0) && (level <= 3)
-       then "\\" ++ (concat (replicate (level - 1) "sub")) ++ "section{" ++ 
-            (inlineListToLaTeX (deVerb lst)) ++ "}\n\n"
-       else (inlineListToLaTeX lst) ++ "\n\n"
-blockToLaTeX (Table caption aligns widths heads rows) =
-    let colWidths = map printDecimal widths
-        colDescriptors = concat $ zipWith
-                                  (\width align -> ">{\\PBS" ++ 
-                                  (case align of 
-                                         AlignLeft -> "\\raggedright"
-                                         AlignRight -> "\\raggedleft"
-                                         AlignCenter -> "\\centering"
-                                         AlignDefault -> "\\raggedright") ++
-                                  "\\hspace{0pt}}p{" ++ width ++ 
-                                  "\\textwidth}")
-                                  colWidths aligns
-        headers        = tableRowToLaTeX heads 
-        captionText    = inlineListToLaTeX caption 
-        tableBody      = "\\begin{tabular}{" ++ colDescriptors ++ "}\n" ++
-                         headers ++ "\\hline\n" ++ 
-                         (concatMap tableRowToLaTeX rows) ++ 
-                         "\\end{tabular}\n" 
-        centered str   = "\\begin{center}\n" ++ str ++ "\\end{center}\n" in
-    if null captionText
-      then centered tableBody ++ "\n"
-      else "\\begin{table}[h]\n" ++ centered tableBody ++ "\\caption{" ++
-           captionText ++ "}\n" ++ "\\end{table}\n\n" 
-
-printDecimal :: Float -> String
-printDecimal = printf "%.2f" 
-
-tableRowToLaTeX cols = joinWithSep " & " (map (concatMap blockToLaTeX) cols) ++ "\\\\\n"
-
-listItemToLaTeX list = "\\item " ++ 
-    (concatMap blockToLaTeX list) 
+blockToLaTeX (Header level lst) = do
+  text <- inlineListToLaTeX (deVerb lst)
+  return $ if (level > 0) && (level <= 3)
+              then "\\" ++ (concat (replicate (level - 1) "sub")) ++ 
+                   "section{" ++ text ++ "}\n\n"
+              else text ++ "\n\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 ++ 
+                                "\\textwidth}")
+                                colWidths aligns
+  let tableBody = "\\begin{tabular}{" ++ colDescriptors ++ "}\n" ++
+                  headers ++ "\\hline\n" ++ concat rows' ++ "\\end{tabular}\n" 
+  let centered str   = "\\begin{center}\n" ++ str ++ "\\end{center}\n"
+  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 null captionText
+              then centered tableBody ++ "\n"
+              else "\\begin{table}[h]\n" ++ centered tableBody ++ "\\caption{" ++
+                   captionText ++ "}\n" ++ "\\end{table}\n\n" 
+
+blockListToLaTeX lst = mapM blockToLaTeX lst >>= (return . concat)
+
+tableRowToLaTeX cols = 
+  mapM blockListToLaTeX cols >>= (return . (++ "\\\\\n") . (joinWithSep " & "))
+
+listItemToLaTeX lst = blockListToLaTeX lst >>= (return . ("\\item "++)) 
+
+defListItemToLaTeX (term, def) = do
+    term' <- inlineListToLaTeX term
+    def'  <- blockListToLaTeX def
+    return $ "\\item[" ++ substitute "]" "\\]" term' ++ "] " ++ def'
 
 -- | Convert list of inline elements to LaTeX.
 inlineListToLaTeX :: [Inline]  -- ^ Inlines to convert
-                  -> String
+                  -> State WriterState String
 inlineListToLaTeX lst = 
-  concatMap inlineToLaTeX lst
+  mapM inlineToLaTeX lst >>= (return . concat)
 
 isQuoted :: Inline -> Bool
 isQuoted (Quoted _ _) = True
@@ -179,34 +200,58 @@ isQuoted _ = False
 
 -- | Convert inline element to LaTeX
 inlineToLaTeX :: Inline    -- ^ Inline to convert
-              -> String
-inlineToLaTeX (Emph lst) = "\\emph{" ++ 
-    (inlineListToLaTeX (deVerb lst)) ++ "}"
-inlineToLaTeX (Strong lst) = "\\textbf{" ++ 
-    (inlineListToLaTeX (deVerb lst)) ++ "}"
-inlineToLaTeX (Code str) = "\\verb" ++ [chr] ++ stuffing ++ [chr]
+              -> State WriterState String
+inlineToLaTeX (Emph lst) = do
+  contents <- inlineListToLaTeX (deVerb lst)
+  return $ "\\emph{" ++ contents ++ "}"
+inlineToLaTeX (Strong lst) = do
+  contents <- inlineListToLaTeX (deVerb lst)
+  return $ "\\textbf{" ++ contents ++ "}"
+inlineToLaTeX (Strikeout lst) = do
+  contents <- inlineListToLaTeX (deVerb lst)
+  addToHeader "\\usepackage[normalem]{ulem}"
+  return $ "\\sout{" ++ contents ++ "}"
+inlineToLaTeX (Superscript lst) = do
+  contents <- inlineListToLaTeX (deVerb lst)
+  return $ "\\textsuperscript{" ++ contents ++ "}"
+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 $ "\\textsubscript{" ++ contents ++ "}"
+inlineToLaTeX (Code str) = return $ "\\verb" ++ [chr] ++ stuffing ++ [chr]
                      where stuffing = str 
                            chr      = ((enumFromTo '!' '~') \\ stuffing) !! 0
-inlineToLaTeX (Quoted SingleQuote lst) =
+inlineToLaTeX (Quoted SingleQuote lst) = do
+  contents <- inlineListToLaTeX lst
   let s1 = if (not (null lst)) && (isQuoted (head lst)) then "\\," else ""
-      s2 = if (not (null lst)) && (isQuoted (last lst)) then "\\," else "" in
-  "`" ++ s1 ++ inlineListToLaTeX lst ++ s2 ++ "'"
-inlineToLaTeX (Quoted DoubleQuote lst) =
+  let s2 = if (not (null lst)) && (isQuoted (last lst)) then "\\," else ""
+  return $ "`" ++ s1 ++ contents ++ s2 ++ "'"
+inlineToLaTeX (Quoted DoubleQuote lst) = do
+  contents <- inlineListToLaTeX lst
   let s1 = if (not (null lst)) && (isQuoted (head lst)) then "\\," else ""
-      s2 = if (not (null lst)) && (isQuoted (last lst)) then "\\," else "" in
-  "``" ++ s1 ++ inlineListToLaTeX lst ++ s2 ++ "''"
-inlineToLaTeX Apostrophe = "'"
-inlineToLaTeX EmDash = "---"
-inlineToLaTeX EnDash = "--"
-inlineToLaTeX Ellipses = "\\ldots{}"
-inlineToLaTeX (Str str) = stringToLaTeX str
-inlineToLaTeX (TeX str) = str
-inlineToLaTeX (HtmlInline str) = ""
-inlineToLaTeX (LineBreak) = "\\\\\n"
-inlineToLaTeX Space = " "
-inlineToLaTeX (Link text (src, tit)) = 
-    "\\href{" ++ src ++ "}{" ++ (inlineListToLaTeX (deVerb text)) ++ "}"
-inlineToLaTeX (Image alternate (source, tit)) = 
-    "\\includegraphics{" ++ source ++ "}" 
-inlineToLaTeX (Note contents) = 
-    "\\footnote{" ++ (stripTrailingNewlines $ concatMap blockToLaTeX contents)  ++ "}"
+  let s2 = if (not (null lst)) && (isQuoted (last lst)) then "\\," else ""
+  return $ "``" ++ s1 ++ contents ++ s2 ++ "''"
+inlineToLaTeX Apostrophe = return "'"
+inlineToLaTeX EmDash = return "---"
+inlineToLaTeX EnDash = return "--"
+inlineToLaTeX Ellipses = return "\\ldots{}"
+inlineToLaTeX (Str str) = return $ stringToLaTeX str
+inlineToLaTeX (TeX str) = return str
+inlineToLaTeX (HtmlInline str) = return ""
+inlineToLaTeX (LineBreak) = return "\\\\\n"
+inlineToLaTeX Space = return " "
+inlineToLaTeX (Link text (src, tit)) = do
+  contents <- inlineListToLaTeX (deVerb text)
+  addToHeader "\\usepackage[breaklinks=true]{hyperref}"
+  return $ "\\href{" ++ src ++ "}{" ++ contents ++ "}"
+inlineToLaTeX (Image alternate (source, tit)) = do
+  addToHeader "\\usepackage{graphicx}"
+  return $ "\\includegraphics{" ++ source ++ "}" 
+inlineToLaTeX (Note contents) = do
+  addToHeader "% This is needed for code blocks in footnotes:\n\
+              \\\usepackage{fancyvrb}\n\\VerbatimFootnotes"
+  contents' <- blockListToLaTeX contents
+  return $ "\\footnote{" ++ stripTrailingNewlines contents'  ++ "}"
+