From: frank <mjzanis@...>
Date: 2006-02-14T03:13:25+09:00
Subject: Re: tree structures

Okay, so I need to approach this head on from an OO standpoint.  I have
Ruby Way and Programming Ruby.

With the program I have written so far, I parsed the tree information
into a set of linked lists (see below). I realize this may not be the
best way to begin this program.  I need to embrace classes and
represent the tree as an object.  I am looking over the example in the
Ruby Way on binary trees. I get what is going on with Hal Fultons
examples.  But it seems like there is a huge gulf between my procedural
thinking and an OO thinking with regard to this tree structure.  How
would you represent a linked list in Ruby?

In other words, would it be possible to convert the following
procedural Ruby code into OO ruby so that I would be able to "get it".
Or are there equivalent examples procedural to OO. I mean, what I have
written is awful looking compared to the class Node you posted
earlier...and while I understand the ideas of instance variables and
self and classes methods etc.  I am struggling to get them right in my
head.

-frank

This is not the full program but enough to see what I am trying to
accomplish.
#!/usr/bin/ruby -w

class Integer
  def odd?
  	self % 2 == 0
  	end
  end

#class Integer
#  def even?() self.[](0) == 0 end
#  def odd?() self.[](0) == 1 end
#end

tree =
"(((aa:0.490,bb:0.50):0.70,cc:0.85):0.90,(ee:0.95,dd:0.99):0.100);"
	print "here is the tree", tree, "\n"

tree_array = tree.scan(/[a-z]+|\d+\.\d+|[(,);]/)

tree_array_size = tree_array.size  # want to use this but need to parse
the tree file better
#initializing an array for a linked list so that I can begin traversing
nodes

leaf = Array.new
node = Array.new
left = Array.new
right = Array.new
ancestor = Array.new
branch = Array.new

m = 0		# a counter used for assigning numbers to nodes
i = 0		#counter for reading through all the elements of a newick tree
while i < tree_array_size

	if tree_array[i] == '(' && i == 0

		print "ROOT", "\n"


		i += 1
		m += 1

		left_m = m*2
		right_m = m*2+1


		node[m] =[]
		left[left_m] = []
		right[right_m] = []

	elsif tree_array[i] == '(' && i != 0

		print "               UP_PASS", "\n"

		i += 1
		m = m*2


		if node[m] == nil

			left_m = m*2
			right_m = m*2+1



			node[m] = []
			left[left_m] = []
			right[right_m] = []
			ancestor[m] == node[m/2]


			print "node is     ", m, "\n"
			print "left    ", left_m, "\n"
			print "right  ", right_m, "\n"

				if m.odd?  != true

					print "ancestor odd is  ", (m-1)/2, "\n"
				else

					print "ancestor is  ", m/2, "\n"
				end

		elsif node[m] != nil

			m = m/2


			print "node already defined looking RIGHT on the tree", "\n"

			m = m*2+1

			left_m = m*2
			right_m = m*2+1


			node[m] = []
			left[left_m] = []
			right[right_m] = []
			ancestor[m] == node[m/2]


			print "node is     ", m, "\n"
			print "left    ", left_m, "\n"
			print "right  ", right_m, "\n"

				if m.odd?  != true

					print "ancestor odd is  ", (m-1)/2, "\n"
				else

					print "ancestor is  ", m/2, "\n"
				end
			
		else	
			
			print "NO doesn't work", "\n"
		end
	


.......