From: Nicholas Paul Johnson <nickjohnson@...>
Date: 2004-04-04T17:58:04+09:00
Subject: recursion w/ blocks; *this

Hello again,

First is, does Ruby have anything equivalent to C++'s `this' pointer?  
I've tried the docs, but don't know what to look for other than 'this'...

Second, if I were to write a method that accepts a block, and would like 
to be able to recurse in that method while allowing each of the recursions 
to use the same block, how would I do that?  

As an example, suppose I have a tree data structure (below), such that
each node has two children: a and b.  I want to create an ``each'' method.  
Ideally, I would yield with ``this,'' and then would recurse to ``each''
on every child of that node.

# this doesnt work for so many reasons :)
class Node
	def initialize(me,a,b)
		@me = me
		@a = a
		@b = b
	end

	def each
	
		# @this represents the calling object (see 1st question)
		yield @this

		# ideally, the same block would get passed to each of 
		# these sub calls
		@aB.each
		@b.each
	end
end


Thanks y'all,
-- 
Nicholas Paul Johnson
nickjohnsonSPAM^H^H^H^H@virginia.edu
http://manjac.ath.cx/nick
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