fun check_destination destination =

     fun write_module width (SOME destination) (modlname, content) =

       (File.check destination; destination);

           let

     fun write_module width destination (modlname, content) =

             val _ = File.check destination;

       let

             val filename = case modlname

         val filename = case modlname

              of "" => Path.explode "Main.hs"

          of "" => Path.explode "Main.hs"

               | _ => (Path.ext "hs" o Path.explode o implode o separate "/"

           | _ => (Path.ext "hs" o Path.explode o implode o separate "/"

                     o Long_Name.explode) modlname;

                 o Long_Name.explode) modlname;

             val pathname = Path.append destination filename;

         val pathname = Path.append destination filename;

             val _ = File.mkdir_leaf (Path.dir pathname);

         val _ = File.mkdir_leaf (Path.dir pathname);

           in File.write pathname

       in File.write pathname

             ("{-# OPTIONS_GHC -fglasgow-exts #-}\n\n"

         ("{-# OPTIONS_GHC -fglasgow-exts #-}\n\n"

               ^ string_of_pretty width content)

           ^ string_of_pretty width content)

           end

       end

       | write_module width NONE (_, content) = writeln_pretty width content;

       (fn width => (fn NONE => K () o map (writeln_pretty width o snd)

       (fn width => fn destination => K () o map (write_module width destination))

         | SOME file => K () o map (write_module width (check_destination file))))

       (fn width => rpair [] o cat_lines o map (string_of_pretty width o snd))

       (fn width => (rpair [] o cat_lines o map (string_of_pretty width o snd)))