Markdown writer: More improvements to 'plain' output, updated tests.

Math now appears in unicode if possible, without the distracting
italics around identifiers.

Blank lines around headers are more consistent.

Footnotes appear in regular [n] style.

1 files changed, 26 insertions, 21 deletions

diff --git a/src/Text/Pandoc/Writers/Markdown.hs b/src/Text/Pandoc/Writers/Markdown.hs
index 41bec8b87..ab87988b8 100644
--- a/src/Text/Pandoc/Writers/Markdown.hs
+++ b/src/Text/Pandoc/Writers/Markdown.hs
@@ -37,7 +37,7 @@ import Text.Pandoc.Templates (renderTemplate')
 import Text.Pandoc.Shared
 import Text.Pandoc.Writers.Shared
 import Text.Pandoc.Options
-import Text.Pandoc.Parsing hiding (blankline, char, space)
+import Text.Pandoc.Parsing hiding (blankline, blanklines, char, space)
 import Data.List ( group, isPrefixOf, find, intersperse, transpose, sortBy )
 import Data.Char ( isSpace, isPunctuation, toUpper )
 import Data.Ord ( comparing )
@@ -79,6 +79,9 @@ writePlain opts document =
                  writerExtensions = Set.delete Ext_escaped_line_breaks $
                                     Set.delete Ext_pipe_tables $
                                     Set.delete Ext_raw_html $
+                                    Set.delete Ext_footnotes $
+                                    Set.delete Ext_tex_math_dollars $
+                                    Set.delete Ext_citations $
                                     writerExtensions opts }
               document) def{ stPlain = True }
 
@@ -171,7 +174,7 @@ pandocToMarkdown opts (Pandoc meta blocks) = do
                then tableOfContents opts headerBlocks
                else empty
   -- Strip off final 'references' header if markdown citations enabled
-  let blocks' = if not isPlain && isEnabled Ext_citations opts
+  let blocks' = if isEnabled Ext_citations opts
                    then case reverse blocks of
                              (Div (_,["references"],_) _):xs -> reverse xs
                              _ -> blocks
@@ -355,11 +358,11 @@ blockToMarkdown opts (Header level attr inlines) = do
   let setext = writerSetextHeaders opts
   return $ nowrap
          $ case level of
-            1 | plain -> blankline <> text "\n\n" <> contents <> blankline <> text "\n"
+            1 | plain -> blanklines 3 <> contents <> blanklines 2
               | setext ->
                   contents <> attr' <> cr <> text (replicate (offset contents) '=') <>
                   blankline
-            2 | plain -> blankline <> text "\n" <> contents <> blankline
+            2 | plain -> blanklines 2 <> contents <> blankline
               | setext ->
                   contents <> attr' <> cr <> text (replicate (offset contents) '-') <>
                   blankline
@@ -695,23 +698,15 @@ inlineToMarkdown opts (Strikeout lst) = do
               then "~~" <> contents <> "~~"
               else "<s>" <> contents <> "</s>"
 inlineToMarkdown opts (Superscript lst) = do
-  plain <- gets stPlain
-  if plain
-     then inlineListToMarkdown opts lst
-     else do
-       contents <- inlineListToMarkdown opts $ walk escapeSpaces lst
-       return $ if isEnabled Ext_superscript opts
-                   then "^" <> contents <> "^"
-                   else "<sup>" <> contents <> "</sup>"
+  contents <- inlineListToMarkdown opts $ walk escapeSpaces lst
+  return $ if isEnabled Ext_superscript opts
+              then "^" <> contents <> "^"
+              else "<sup>" <> contents <> "</sup>"
 inlineToMarkdown opts (Subscript lst) = do
-  plain <- gets stPlain
-  if plain
-     then inlineListToMarkdown opts lst
-     else do
-       contents <- inlineListToMarkdown opts $ walk escapeSpaces lst
-       return $ if isEnabled Ext_subscript opts
-                   then "~" <> contents <> "~"
-                   else "<sub>" <> contents <> "</sub>"
+  contents <- inlineListToMarkdown opts $ walk escapeSpaces lst
+  return $ if isEnabled Ext_subscript opts
+              then "~" <> contents <> "~"
+              else "<sub>" <> contents <> "</sub>"
 inlineToMarkdown opts (SmallCaps lst) = do
   plain <- gets stPlain
   if plain
@@ -753,7 +748,11 @@ inlineToMarkdown opts (Math InlineMath str)
       return $ "\\(" <> text str <> "\\)"
   | isEnabled Ext_tex_math_double_backslash opts =
       return $ "\\\\(" <> text str <> "\\\\)"
-  | otherwise = inlineListToMarkdown opts $ texMathToInlines InlineMath str
+  | otherwise = do
+    plain <- gets stPlain
+    inlineListToMarkdown opts $
+      (if plain then makeMathPlainer else id) $
+      texMathToInlines InlineMath str
 inlineToMarkdown opts (Math DisplayMath str)
   | isEnabled Ext_tex_math_dollars opts =
       return $ "$$" <> text str <> "$$"
@@ -853,3 +852,9 @@ inlineToMarkdown opts (Note contents) = do
   if isEnabled Ext_footnotes opts
      then return $ "[^" <> ref <> "]"
      else return $ "[" <> ref <> "]"
+
+makeMathPlainer :: [Inline] -> [Inline]
+makeMathPlainer = walk go
+  where
+  go (Emph xs) = Span nullAttr xs
+  go x = x