Added Ext_fenced_code_attributes.

src/Text/Pandoc/Options.hs

@@ -65,6 +65,7 @@ data Extension =
     | Ext_tex_math_double_backslash  -- ^ TeX math btw \\(..\\) \\[..\\]
     | Ext_latex_macros        -- ^ Parse LaTeX macro definitions (for math only)
     | Ext_fenced_code_blocks  -- ^ Parse fenced code blocks
+    | Ext_fenced_code_attributes  -- ^ Allow attributes on fenced code blocks
     | Ext_inline_code_attributes  -- ^ Allow attributes on inline code
     | Ext_markdown_in_html_blocks -- ^ Interpret as markdown inside HTML blocks
     | Ext_markdown_attribute      -- ^ Interpret text inside HTML as markdown
@@ -105,6 +106,7 @@ pandocExtensions = Set.fromList
   , Ext_tex_math_dollars
   , Ext_latex_macros
   , Ext_fenced_code_blocks
+  , Ext_fenced_code_attributes
   , Ext_inline_code_attributes
   , Ext_markdown_in_html_blocks
   , Ext_escaped_line_breaks

src/Text/Pandoc/Readers/Markdown.hs

@@ -379,7 +379,7 @@ indentedLine = indentSpaces >> manyTill anyChar newline >>= return . (++ "\n")
 
 blockDelimiter :: (Char -> Bool)
                -> Maybe Int
-               -> Parser [Char] st (Int, (String, [String], [(String, String)]), Char)
+               -> Parser [Char] ParserState (Int, (String, [String], [(String, String)]), Char)
 blockDelimiter f len = try $ do
   c <- lookAhead (satisfy f)
   size <- case len of
@@ -387,9 +387,11 @@ blockDelimiter f len = try $ do
               Nothing -> count 3 (char c) >> many (char c) >>=
                          return . (+ 3) . length
   many spaceChar
-  attr <- option ([],[],[])
-          $ attributes                                     -- ~~~ {.ruby}
-         <|> (many1 alphaNum >>= \x -> return ([],[x],[])) -- github variant ```ruby
+  attr <- option ([],[],[]) $ do
+            guardEnabled Ext_fenced_code_attributes
+            attributes                    -- ~~~ {.ruby}
+             <|> (many1 alphaNum >>= \x ->
+                    return ([],[x],[]))   -- github variant ```ruby
   blankline
   return (size, attr, c)
 

src/Text/Pandoc/Writers/Markdown.hs

@@ -297,8 +297,10 @@ blockToMarkdown opts (CodeBlock attribs str) = return $
           (tildes <> space <> attrs <> cr <> text str <>
                   cr <> tildes) <> blankline
      else nest (writerTabStop opts) (text str) <> blankline
-   where tildes  = text "~~~~"
-         attrs = attrsToMarkdown attribs
+   where tildes = text "~~~~"
+         attrs  = if isEnabled Ext_fenced_code_attributes opts
+                     then attrsToMarkdown attribs
+                     else empty
 blockToMarkdown opts (BlockQuote blocks) = do
   st <- get
   -- if we're writing literate haskell, put a space before the bird tracks