From: Michal Rokos <rokosm@...>
Date: 2002-02-06T09:41:06+09:00
Subject: Re: Ruby extension for IBM Via Voice TTS

Hello,

Mike Hall <mghall@enteract.com> wrote:
> There's many voice and synthesis parameters that control 
> the speaking voice, like pitch, volume, speed, head, gender, etc.
> 
> What's a good "Ruby way" to add these?
> 
> - define general set_param / get_param methods
>        and write higher-level methods in Ruby?


	I use this. For example: .from_ary(array) is implemented in 'C'
	space, but .from_hash(hash) is in 'Ruby' space and calls
	.from_ary()
	
> - define the individual methods in C?

	I did not understand the question.
	
> - make them look and act like instance variables?

	Of course. I think that you should had in mind that you're
	making something for 'Ruby' people - so it should fit the Ruby's
	practices.

	So I have:

	xxx_set_x() and xxx_get_x() in 'C'

	The glue is:

	rb_define_class(c, "XXX", rb_cObject);
	rb_define_method(c, "x", xxx_get_x, ...);
	rb_define_method(c, "x=" xxx_set_x, ...);

	in 'C'.


	Maybe I'm wrong, but you should also use 'new' and 'initialize'
	methods for your objects. 'new' should allocate all memory for
	obj. and 'initialize' should init it.

	rb_define_singleton_method(c, "new", xxx_s_new, -1);
	rb_define_method(c, "initialize", xxx_initialize, -1);

	and

	static VALUE xxx_s_new(int argc, VALUE *argv, VALUE klass)
	{
		VALUE obj;
		
		... /* ALLOC MEM */
		
		obj = Data_..._Struct(...);
		
		rb_obj_call_init(obj, argc, argv);
		
		return obj;
	}

	static VALUE xxx_initialize(int argc, VALUE *argv, VALUE self)
	{
		Data_Get_Struct(self, ...);
		
		rb_scan_args(argc, argv, ...);

		... /* INIT IT */
		
		return self;
	}



	I hope it helped.

		Michal
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Michal Rokos                           Czech Technical University, Prague
E-mail: m.rokos@sh.cvut.cz         Jabber: majkl@jabber.cz, ICQ: 36118339
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