From: Dave Thomas <Dave@...>
Date: 2000-12-20T11:39:14+09:00
Subject: [ruby-talk:7731] Re: Ruby enhancement request

"Lyle Johnson" <ljohnson@resgen.com> writes:

> Because the format string for rb_scan_args() only uses single digits to
> determine the number of required and optional arguments this means that you
> can't have more than nine of either, right?

If it's a fixed number, you can have up to 17 (the argc parameter to
rb_define_method).

Another approach when there are a large number of arguments is to pass trailing
arguments in as a hash, using the fact that Ruby automatically gathers 
up key=>value pairs at the end of a parameter list:

  fx_create_window("fred", "Bert", 100, 200, FX::MAPPING => FIXED,
                   FX::ICON => 'dave.ico')

This would be picked up by a method with a signature such as

  def fx_create_window(name, title, x, y, opts)
    if opts[FX::MAPPING] ...


This is nice if the trailing arguments are not always needed. It will
also convert easily when Matz introduces keyword arguments.


Just a thought.


Dave