Support for math in RST reader and writer.

Inline math uses the :math:`...` construct.

Display math uses

  .. math:: ...

or if multilin

  .. math::

     ...

These seem to be supported now by rst2latex.py.

src/Text/Pandoc/Readers/RST.hs

@@ -363,18 +363,18 @@ customCodeBlock = try $ do
 
 -- | The 'math' directive (from Sphinx) for display math.
 mathBlock :: GenParser Char st Block
-mathBlock = mathBlockMultiline <|> mathBlockOneLine
+mathBlock = try $ do
+  string ".. math::"
+  mathBlockMultiline <|> mathBlockOneLine
 
 mathBlockOneLine :: GenParser Char st Block
 mathBlockOneLine = try $ do
-  string ".. math:"
   result <- manyTill anyChar newline
   blanklines
   return $ Para [Math DisplayMath $ removeLeadingTrailingSpace result]
 
 mathBlockMultiline :: GenParser Char st Block
 mathBlockMultiline = try $ do
-  string ".. math::"
   blanklines
   result <- indentedBlock
   -- a single block can contain multiple equations, which need to go
@@ -384,7 +384,8 @@ mathBlockMultiline = try $ do
   let startsWithColon (':':_) = True
       startsWithColon _       = False
   let lns' = dropWhile startsWithColon lns
-  let eqs = map unwords $ filter (not . null) $ splitBy null lns'
+  let eqs = map (removeLeadingTrailingSpace . unlines)
+            $ filter (not . null) $ splitBy null lns'
   return $ Para $ map (Math DisplayMath) eqs
 
 lhsCodeBlock :: GenParser Char ParserState Block

src/Text/Pandoc/Writers/RST.hs

@@ -286,9 +286,11 @@ inlineToRST (Str str) = return $ text $ escapeString str
 inlineToRST (Math t str) = do
   modify $ \st -> st{ stHasMath = True }
   return $ if t == InlineMath
-              then ":math:`" <> text str <> "`\\ "
-              else blankline $$ ".. math::" $$ blankline $$
-                   nest 3 (text str) $$ blankline
+              then ":math:`" <> text str <> "`" <> beforeNonBlank "\\ "
+              else if '\n' `elem` str
+                   then blankline $$ ".. math::" $$
+                        blankline $$ nest 3 (text str) $$ blankline
+                   else blankline $$ (".. math:: " <> text str) $$ blankline
 inlineToRST (RawInline _ _) = return empty
 inlineToRST (LineBreak) = return cr -- there's no line break in RST
 inlineToRST Space = return space

tests/rst-reader.native

@@ -305,4 +305,11 @@ Pandoc (Meta {docTitle = [Str "Pandoc",Space,Str "Test",Space,Str "Suite",Str ":
 ,Para [Note [Para [Str "Note",Space,Str "with",Space,Str "continuation",Space,Str "line",Str "."]]]
 ,Para [Note [Para [Str "Note",Space,Str "with"],Para [Str "continuation",Space,Str "block",Str "."]]]
 ,Para [Note [Para [Str "Note",Space,Str "with",Space,Str "continuation",Space,Str "line"],Para [Str "and",Space,Str "a",Space,Str "second",Space,Str "para",Str "."]]]
-,Para [Str "Not",Space,Str "in",Space,Str "note",Str "."]]
+,Para [Str "Not",Space,Str "in",Space,Str "note",Str "."]
+,Header 1 [Str "Math"]
+,Para [Str "Some",Space,Str "inline",Space,Str "math",Space,Math InlineMath "E=mc^2",Str ".",Space,Str "Now",Space,Str "some",Space,Str "display",Space,Str "math",Str ":"]
+,Para [Math DisplayMath "E=mc^2"]
+,Para [Math DisplayMath "E = mc^2"]
+,Para [Math DisplayMath "E = mc^2",Math DisplayMath "\\alpha = \\beta"]
+,Para [Math DisplayMath "E &= mc^2\\\\\nF &= \\pi E",Math DisplayMath "F &= \\gamma \\alpha^2"]
+,Para [Str "All",Space,Str "done",Str "."]]

tests/rst-reader.rst

@@ -536,3 +536,32 @@ Footnotes
 
 Not in note.
 
+Math
+====
+
+Some inline math :math:`E=mc^2`\ .  Now some
+display math:
+
+.. math:: E=mc^2
+
+.. math::
+
+   E = mc^2
+
+.. math::
+
+   E = mc^2
+
+   \alpha = \beta
+
+.. math::
+   :label hithere
+   :nowrap
+
+   E &= mc^2\\
+   F &= \pi E
+
+   F &= \gamma \alpha^2
+
+All done.
+

tests/writer.rst

@@ -598,15 +598,16 @@ LaTeX
 =====
 
 -  
--  :math:`$2+2=4$`
--  :math:`$x \in y$`
--  :math:`$\alpha \wedge \omega$`
--  :math:`$223$`
--  :math:`$p$`-Tree
+-  :math:`2+2=4`
+-  :math:`x \in y`
+-  :math:`\alpha \wedge \omega`
+-  :math:`223`
+-  :math:`p`\ -Tree
 -  Here’s some display math:
-   :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:
-   :math:`$\alpha + \omega \times x^2$`.
+
+   .. 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: :math:`\alpha + \omega \times x^2`\ .
 
 These shouldn’t be math: