Make markdown and github writers respect the emoji extension.

src/Text/Pandoc/Writers/CommonMark.hs

@@ -304,6 +304,11 @@ inlineToNodes opts (Math mt str) =
               (node (HTML_INLINE (T.pack ("\\(" ++ str ++ "\\)"))) [] :)
             DisplayMath ->
               (node (HTML_INLINE (T.pack ("\\[" ++ str ++ "\\]"))) [] :)
+inlineToNodes opts (Span ("",["emoji"],kvs) [Str s]) = do
+  case lookup "data-emoji" kvs of
+       Just emojiname | isEnabled Ext_emoji opts ->
+            (node (TEXT (":" <> T.pack emojiname <> ":")) [] :)
+       _ -> (node (TEXT (T.pack s)) [] :)
 inlineToNodes opts (Span attr ils) =
   let nodes = inlinesToNodes opts ils
       op = tagWithAttributes opts True False "span" attr

src/Text/Pandoc/Writers/Markdown.hs

@@ -982,6 +982,11 @@ isRight (Left  _) = False
 
 -- | Convert Pandoc inline element to markdown.
 inlineToMarkdown :: PandocMonad m => WriterOptions -> Inline -> MD m Doc
+inlineToMarkdown opts (Span ("",["emoji"],kvs) [Str s]) = do
+  case lookup "data-emoji" kvs of
+       Just emojiname | isEnabled Ext_emoji opts ->
+            return $ ":" <> text emojiname <> ":"
+       _ -> inlineToMarkdown opts (Str s)
 inlineToMarkdown opts (Span attrs ils) = do
   plain <- asks envPlain
   contents <- inlineListToMarkdown opts ils

test/command/emoji.md

@@ -0,0 +1,27 @@
+```
+% pandoc -t markdown+emoji -f markdown+emoji
+:smile:
+^D
+:smile:
+```
+
+```
+% pandoc -t markdown-emoji -f markdown+emoji
+:smile:
+^D
+😄
+```
+
+```
+% pandoc -t gfm -f markdown+emoji
+:smile:
+^D
+:smile:
+```
+
+```
+% pandoc -t gfm-emoji -f markdown+emoji
+:smile:
+^D
+😄
+```