Trying to get nested bold and italic to work

src/MdToHTML.hs

@@ -157,8 +157,12 @@ parseBold = parseBoldWith asteriskBold <|> parseBoldWith underscoreBold
   where
     parseBoldWith delim = do
       string delim
-      inside <- someTill parseLineToken $ string delim
+      inside <- parseNestedThenLineToken delim
       return (Bold (Line inside))
+    parseNestedThenLineToken delim = do
+      first <- fallthroughParser [parseItalic, parseLineToken]
+      rest <- fallthroughParser [singleton <$> parseItalic, singleton <$> string delim >> return mempty, liftA2 (:) parseLineToken $ parseNestedThenLineToken delim]
+      return (first : rest)
 
 -- Parse italic text
 parseItalic :: Parser MdToken
@@ -166,8 +170,12 @@ parseItalic = parseItalicWith '*' <|> parseItalicWith '_'
   where
     parseItalicWith delim = do
       char delim
-      inside <- someTill parseLineToken (char delim)
+      inside <- parseNestedThenLineToken delim
       return (Italic (Line inside))
+    parseNestedThenLineToken delim = do
+      first <- fallthroughParser [parseBold, parseLineToken]
+      rest <- fallthroughParser [singleton <$> parseBold, singleton <$> char delim >> return mempty, liftA2 (:) parseLineToken $ parseNestedThenLineToken delim]
+      return (first : rest)
 
 -- Parse strikethrough text
 parseStrikethrough :: Parser MdToken