RST reader/writer: support unknown interpreted text roles...

...by parsing them as Span with "role" attributes.
This way they can be manipulated in the AST.

Closes #3407.

2 files changed, 8 insertions, 5 deletions

diff --git a/src/Text/Pandoc/Readers/RST.hs b/src/Text/Pandoc/Readers/RST.hs
index 0f594fe1b..190b065fb 100644
--- a/src/Text/Pandoc/Readers/RST.hs
+++ b/src/Text/Pandoc/Readers/RST.hs
@@ -1399,10 +1399,8 @@ renderRole contents fmt role attr = case role of
         case M.lookup custom customRoles of
             Just (newRole, newFmt, newAttr) ->
                 renderRole contents newFmt newRole newAttr
-            Nothing -> do
-                pos <- getPosition
-                logMessage $ SkippedContent (":" ++ custom ++ ":") pos
-                return $ B.str contents -- Undefined role
+            Nothing -> -- undefined role
+                return $ B.spanWith ("",[],[("role",role)]) (B.str contents)
  where
    titleRef ref = return $ B.str ref -- FIXME: Not a sensible behaviour
    rfcLink rfcNo = B.link rfcUrl ("RFC " ++ rfcNo) $ B.str ("RFC " ++ rfcNo)
diff --git a/src/Text/Pandoc/Writers/RST.hs b/src/Text/Pandoc/Writers/RST.hs
index 17f5b3f91..8c941f568 100644
--- a/src/Text/Pandoc/Writers/RST.hs
+++ b/src/Text/Pandoc/Writers/RST.hs
@@ -439,7 +439,12 @@ inlineListToRST lst =
 
 -- | Convert Pandoc inline element to RST.
 inlineToRST :: PandocMonad m => Inline -> RST m Doc
-inlineToRST (Span _ ils) = inlineListToRST ils
+inlineToRST (Span (_,_,kvs) ils) = do
+  contents <- inlineListToRST ils
+  return $
+    case lookup "role" kvs of
+          Just role -> ":" <> text role <> ":`" <> contents <> "`"
+          Nothing   -> contents
 inlineToRST (Emph lst) = do
   contents <- inlineListToRST lst
   return $ "*" <> contents <> "*"