From: Tanaka Akira <akr@...17n.org>
Date: 2000-12-26T13:39:27+09:00
Subject: [ruby-dev:11852] local variable extent problem?

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test = Test.new
Retriever.new {|retriever|
  var = "val"
  test.get(retriever) {|result|
    print "#{result}\n"
    print "#{var}\n"
  }
}

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% ./tst
test
./tst:52: undefined local variable or method `var' for #<Object:0x8106cd8> (NameError)
        from ./tst:31:in `join'
        from ./tst:31:in `initialize'
        from ./tst:48:in `new'
        from ./tst:48
% /usr/local/bin/ruby -v
ruby 1.6.1 (2000-09-27) [i386-freebsdelf4.0]
% 

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#!/usr/local/bin/ruby

require 'thread'
require 'net/http'

class Test
  def get(retriever)
    Receptor.new(retriever) {|result|
      yield result
    }
  end
end

class Receptor
  def initialize(retriever, &proc)
    @proc = proc
    retriever.enqueue(self)
  end

  def finished
    @proc.call(:test)
  end
end

class Retriever
  def initialize
    @queue = Queue.new
    @thread = Thread.new {get_loop}
    yield self
    @queue.push(nil)
    @thread.join
  end

  def enqueue(dest)
    @queue.push dest
  end

  def get_loop
    while dest = @queue.pop
      r, b = Net::HTTP.new("cvs.m17n.org", 80).get("/")
      dest.finished
    end
    @queue.push nil
  end
end

test = Test.new
Retriever.new {|retriever|
  var = "val"
  test.get(retriever) {|result|
    print "#{result}\n"
    print "#{var}\n"
  }
}
-- 
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