class_without_end.rb

EndNo = Class.new {
  define_method(:if_example) { |condition|
    (condition && ->{
      "yeah, true!"
    } || ->{
      "why not?"
    }).call
  }

  define_method(:while_example) { |limit|
    (whiler = ->{
      limit > 0 && ->{
        limit -= 1
        puts limit
        whiler.call
      }.call
    }).call
  }

  define_method(:for_example) { |limit|
    limit.times { |i| puts i }
  }
}

EndNo.new.if_example(true)
EndNo.new.if_example(false)

EndNo.new.while_example(5)

EndNo.new.for_example(5)