From: seebs@... (Peter Seebach)
Date: 2007-05-26T21:18:46+09:00
Subject: Re: Forward references?

In message <3a94cf510705260514u31029d2fr95bb8f96c5520c23@mail.gmail.com>, "Francis Cianfrocca" 
writes:
>In this construction you're defining B inside the naming context of A, which
>doesn't exist when the *parser* (which obeys Ruby scoping rules like any
>other Ruby program) needs to use the value of A.

Right.  Thus my forward-reference solution:

	class A
	end

	class A::B
	...
	end

	class A
	...
	end

Which is mostly picked up from C's "struct foo;" forward reference
declarations.

>You see the difference? You don't have to define class A before you define
>class B, but you DO need to *declare* A before you can present it to Ruby's
>parser in a construction like A::xxx.

Right.

>Of course your original question related to style rather than parser
>behavior. You don't say whether you come from a Java background, where the
>relationship between classes and source files is much stricter than it is in
>Ruby.

Mostly C and perl, although I read and write a fair number of languages
now.

>module MyApplication
>    class A
>        def initialize
>            @b = B.new
>        end
>    end
>end

>#------------------------------

>module MyApplication
>    class A
>        class B
>        end
>    end
>end

Makes sense.  I'm now doing:

	module MyApplication
		class A
		...
		end

		class B
		...
		end
	end

because really, I don't have an unambiguous top-level class, so using a module
for namespace is clearer.

-s