From: "Simon Kröger" <SimonKroeger@...>
Date: 2005-09-03T07:26:31+09:00
Subject: Re: Idiomatic conversion of yielding block to array

Simon Kr�ger wrote:
> You don't need the to_a but still zip will create 3 arrays.

this does not, but its still not very ruby like:
-------------------------------------------------------------
s1 = ['this', 'is', 'a', 'test'].join("\n")
s2 = ['this', 'is', 'the', 'test'].join("\n")

q1, q2 = SizedQueue.new(1), SizedQueue.new(1)
Thread.new {s1.each_line {|l| q1 << l}; q1 << nil}
Thread.new {s2.each_line {|l| q2 << l}; q2 << nil}

line_no = 0
while true
   line_no += 1
   t1, t2 = q1.pop, q2.pop
   break if !t1 || !t2
   puts "difference on line #{line_no}" if t1 != t2
end
-------------------------------------------------------------

perhaps better, but still kind of hardcore:

-------------------------------------------------------------
require 'enumerator'
require 'thread'

module Enumerable
   def each_zip(other)
     q = SizedQueue.new(1)
     Thread.new {other.each{|l| q << l}}
     self.each{|a| yield a, q.pop}
   end
end

s1 = ['this', 'is', 'a', 'test'].join("\n")
s2 = ['this', 'is', 'the', 'test'].join("\n")

s1.to_enum(:each_line).enum_for(:each_zip,
   s2.to_enum(:each_line)).each_with_index do |t, l|
   puts "difference on line: #{l+1}" if t[0] != t[1]
end
-------------------------------------------------------------

food for thoughts...

Simon