Add pygments colors to pandoc stylesheet

pygments.lua

@@ -6,8 +6,9 @@ return {
       _with_0:write(block.text)
       _with_0:close()
     end
+    local cmd = "pygmentize -f html -O style=dracula,wrapcode,classprefix=py- -l %s %s"
     if block.classes[1] == "moon" or block.classes[1] == "moonscript" then
-      local p = io.popen(("pygmentize -f html -O style=dracula,wrapcode,classprefix=py- -l moonscript.py %s -x"):format(fname))
+      local p = io.popen((cmd .. " -x"):format("moonscript.py", fname))
       local out = p:read("*a")
       p:close()
       return pandoc.RawBlock("html", out)
@@ -25,10 +26,19 @@ return {
         end
       else
         local status, handle_or_error = pcall(function()
-          return io.popen(("pygmentize -f html -O style=dracula,wrapcode,classprefix=py- -l %s %s"):format(block.classes[1], fname))
+          return io.popen((cmd):format(block.classes[1], fname))
         end)
         local sout = handle_or_error:read("*a")
-        return pandoc.RawBlock("html", sout)
+        if sout:len() == 0 then
+          local cb = pandoc.CodeBlock(block.text, {
+            class = "sourceCode"
+          })
+          return pandoc.Div(cb, {
+            class = "sourceCode"
+          })
+        else
+          return pandoc.RawBlock("html", sout)
+        end
       end
     end
   end