#---
# Excerpted from "Programming Ruby 3.2",
# published by The Pragmatic Bookshelf.
# Copyrights apply to this code. It may not be used to create training material,
# courses, books, articles, and the like. Contact us if you are in doubt.
# We make no guarantees that this code is fit for any purpose.
# Visit https://pragprog.com/titles/ruby6 for more book information.
#---
4.times.map do |number|
  Thread.new(number) do |i|
    raise "Boom!" if i == 1
    print "#{i}\n"
  end
end
puts "Waiting"
sleep 0.1
puts "Done"
