Use an interpreted text role to render math in restructuredText.

See http://www.american.edu/econ/itex2mml/mathhack.rst for the
strategy.


git-svn-id: https://pandoc.googlecode.com/svn/trunk@1168 788f1e2b-df1e-0410-8736-df70ead52e1b

README

@@ -852,6 +852,10 @@ TeX math will be printed in all output formats. In Markdown,
 reStructuredText, LaTeX, and ConTeXt output, it will appear verbatim
 between $ characters.
 
+In reStructuredText output, it will be rendered using an interpreted
+text role `:math:`, as described
+[here](http://www.american.edu/econ/itex2mml/mathhack.rst).
+
 In groff man output, it will be rendered verbatim without $'s.
 
 In RTF and Docbook output, it will be rendered, as far as possible,

Text/Pandoc/Writers/RST.hs

@@ -44,7 +44,7 @@ data WriterState =
   WriterState { stNotes     :: [[Block]]
               , stLinks     :: KeyTable
               , stImages    :: KeyTable
-              , stIncludes  :: [Doc]
+              , stIncludes  :: [String]
               , stOptions   :: WriterOptions
               }
 
@@ -69,12 +69,14 @@ pandocToRST (Pandoc meta blocks) = do
                 then metaBlock $+$ text (writerHeader opts)
                 else empty
   body <- blockListToRST blocks
+  includes <- get >>= (return . concat . stIncludes)
+  let includes' = if null includes then empty else text includes
   notes <- get >>= (notesToRST . reverse . stNotes)
   -- note that the notes may contain refs, so we do them first
   refs <- get >>= (keyTableToRST . reverse . stLinks)
   pics <- get >>= (pictTableToRST . reverse . stImages)
-  return $ head $+$ before' $+$ body $+$ notes $+$ text "" $+$ refs $+$ 
+  return $ head $+$ before' $+$ includes' $+$ body $+$ notes $+$ text "" $+$
-           pics $+$ after'
+           refs $+$ pics $+$ after'
 
 -- | Return RST representation of reference key table.
 keyTableToRST :: KeyTable -> State WriterState Doc
@@ -117,8 +119,11 @@ pictToRST (label, (src, _)) = do
 
 -- | Take list of inline elements and return wrapped doc.
 wrappedRST :: WriterOptions -> [Inline] -> State WriterState Doc
-wrappedRST opts inlines = mapM (wrapIfNeeded opts inlineListToRST)
+wrappedRST opts inlines = do
-                               (splitBy LineBreak inlines) >>= return . vcat
+  lineBreakDoc <- inlineToRST LineBreak  
+  chunks <- mapM (wrapIfNeeded opts inlineListToRST)
+                 (splitBy LineBreak inlines)
+  return $ vcat $ intersperse lineBreakDoc chunks
 
 -- | Escape special characters for RST.
 escapeString :: String -> String
@@ -293,10 +298,18 @@ inlineToRST Apostrophe = return $ char '\''
 inlineToRST Ellipses = return $ text "..."
 inlineToRST (Code str) = return $ text $ "``" ++ str ++ "``"
 inlineToRST (Str str) = return $ text $ escapeString str
-inlineToRST (Math str) = return $ text $ "$" ++ str ++ "$"
+inlineToRST (Math str) = do
+  includes <- get >>= (return . stIncludes)
+  let rawMathRole = ".. role:: math(raw)\n\
+                    \   :format: html latex\n"
+  if not (rawMathRole `elem` includes)
+     then modify $ \st -> st { stIncludes = rawMathRole : includes }
+     else return ()
+  return $ text $ ":math:`$" ++ str ++ "$`"
 inlineToRST (TeX str) = return empty
 inlineToRST (HtmlInline str) = return empty
-inlineToRST (LineBreak) = return $ char ' ' -- RST doesn't have linebreaks 
+inlineToRST (LineBreak) = do
+  return $ empty -- there's no line break in RST
 inlineToRST Space = return $ char ' '
 inlineToRST (Link [Code str] (src, tit)) | src == str ||
                                                 src == "mailto:" ++ str = do

tests/writer.rst

@@ -6,6 +6,9 @@ Pandoc Test Suite
 :Author: Anonymous
 :Date: July 17, 2006
 
+.. role:: math(raw)
+   :format: html latex
+
 This is a set of tests for pandoc. Most of them are adapted from
 John Gruber's markdown test suite.
 
@@ -620,14 +623,14 @@ LaTeX
 
 - 
 - 
--  $2+2=4$
+-  :math:`$2+2=4$`
--  $x \in y$
+-  :math:`$x \in y$`
--  $\alpha \wedge \omega$
+-  :math:`$\alpha \wedge \omega$`
--  $223$
+-  :math:`$223$`
--  $p$-Tree
+-  :math:`$p$`-Tree
--  $\frac{d}{dx}f(x)=\lim_{h\to 0}\frac{f(x+h)-f(x)}{h}$
+-  :math:`$\frac{d}{dx}f(x)=\lim_{h\to 0}\frac{f(x+h)-f(x)}{h}$`
 -  Here's one that has a line break in it:
-   $\alpha + \omega \times x^2$.
+   :math:`$\alpha + \omega \times x^2$`.
 
 These shouldn't be math: