From: Hachenberger Peter <Peter.Hachenberger@...>
Date: 2001-11-13T00:21:52+09:00
Subject: [ruby-talk:24936] Naming conventions

Hello,

I am trying to create an class, which handles arithmetic operations on
triples. I need two constant values for this class looked at the Standard
Library "complex.rb" to see how the constant I=(0,1) is realized in it.
There I found the following:

	def Complex(a, b = 0)
	  if a.kind_of?(Complex) and b == 0
	    a
	  elsif b.kind_of?(Complex)
	    if a.kind_of?(Complex)
	      Complex(a.real-b.image, a.image + b.real)
	    else
	      Complex(a-b.image, b.real)
	    end
	  elsif b == 0 and defined? Complex::Unify
	    a
	  else
	    Complex.new(a, b)
	  end
	end

	class Complex < Numeric

	...

	  def initialize(a, b = 0)
	    raise "non numeric 1st arg `#{a.inspect}'" if !a.kind_of?
Numeric
	    raise "non numeric 2nd arg `#{b.inspect}'" if !b.kind_of?
Numeric
	    @real = a
	    @image = b
	  end

	...

	  I = Complex(0,1)
	  
	  attr :real
	  attr :image
	  
	end

That's quite an interesting way to solve the problem, but i am curios about
the definition of the method Complex. As far as I have read, the naming
convention for methods tells us to begin a method name with a lowercase
Character. What happens here? Why does ruby know, that Complex is a method
call here and not the class name?

Peter