From: Dimitrios Galanakis <galanaki@...>
Date: 2003-10-03T04:47:49+09:00
Subject: Re: newbie question: function overloading

I was expecting an answer like that... I wanted to ask then if operator 
overloading if exactly similar to function overloading.
I would like for example to define my own complex class. In this canse 
the * operator will perform differencly when multiplying a real and a 
complex and when multiplying two complex numbers (this is almost what I 
need to do only the difference is that instead of a complex class I have 
some other class for which it makes sence to multiply objects of that 
class together and with real numbers). In other words how can I simplify 
the following code by removing the ifs?



class complex
	def *(something)
		result=self.dup
		if something.kind_of?(Numeric)
			result.real*=something
			result.imag*=something
			return result
		end
		if something.kind_of(complex)
			result.real=result.real*something.real-result.imag*something.imag
			... etc etc etc
		end

	end

end




Chad Fowler wrote:
> On Fri, 3 Oct 2003, Dimitrios Galanakis wrote:
> 
> # I need to define a method that performs differently when operated on objects
> # of different type (overloading). Currently I use various if's to check for
> # the type of the object as follows:
> # 
> 
> There are really two answers to this:
> 
> 1) Ryan Pavlik has created a library that provides overloading capability 
> like this.  You could give it a try and it might feel right to your C++ 
> ways.
> 2) I would lean more heavily toward this one:  The Ruby Way to accomplish 
> what you're trying to accomplish very likely isn't to check type in this 
> way.  I remember coming to Ruby from C++/Java and wondering why I couldn't 
> do method overloading like this.  My brain was wired into the static 
> typing way of doing things and I even felt like overloading was almost 
> a necessary part of OO.  It didn't take long before I stopped feeling the 
> need for this capability as I started reading existing code and 
> understanding the Ruby idioms better.
> 
> Maybe if you could post a more specific example/statement of what you're 
> trying to accomplish, we could see about helping you with option #2.
> 
> Chad
> 
>