handler:insert-format-handler

This function inserts a format handler.

• (handler:insert-format-handler name pred handler) -> void
      name : string
      pred : (union string (listof string) (string -> boolean))
      handler : (string -> (implements frame:editor<%>))

  The string, name names the format handler for use with handler:find-named-format-handler. If pred is a string, it is matched with the extention of a filename by handler:find-format-handler. If pred is a list of strings, they are each matched with the extension of a filename by handler:find-format-handler. If it is a function, the filename is applied to the function and the functions result determines if this is the handler to use.