Trace message problem

1_repeated_patterns.rb

flavors.each do |f|
  begin
    trace "  #{f.repo_name} #{f.locked_version} ..."
    f.deploy(vimfiles_path)
    trace " done\n"
  rescue
    trace " failed\n"
    raise
  end
end

2_idea.rb

module Enumerable
  def before_each(&tracer)
    vs = each
    Enumerator.new do |y|
      loop do
        v = vs.next
        tracer.call(v)
        y << v
      end
    end
  end

  def after_each(&tracer)
    vs = each
    Enumerator.new do |y|
      loop do
        v = vs.next
        y << v
        tracer.call(v)
      end
    end
  end

  def on_failure(&tracer)
    vs = each
    Enumerator.new do |y|
      v = nil
      begin
        loop do
          v = vs.next
          y << v
          v = nil
        end
      rescue StopIteration
        raise
      rescue
        tracer.call(v)
        raise
      end
    end
  end
end

xs = Object.new
def xs.each
  yield 1
  yield 2
  raise RuntimeError, 'bar!'
  yield 3
end

# xs.to_enum.
# [1, 2, 3].to_enum.
[1, 2, 3].
before_each {|x| puts "before #{x}"}.
after_each {|x| puts "success #{x}"}.
on_failure {|x| puts "failure #{x}"}.
each do |x|
  puts "doing #{x}"
  raise RuntimeError, 'foo!' if x == 3
  puts "done #{x}"
end

2_idea_result.txt

YUKI.N> ruby t.rb
before 1
doing 1
done 1
success 1
before 2
doing 2
done 2
success 2
before 3
doing 3
failure 3
t.rb:53:in `block in <main>': foo! (RuntimeError)
        from t.rb:28:in `<<'
        from t.rb:28:in `block (2 levels) in trace_failure_each'
        from t.rb:24:in `loop'
        from t.rb:24:in `block in trace_failure_each'
        from t.rb:47:in `each'
        from t.rb:47:in `each'
        from t.rb:47:in `<main>'

3_idea.rb

module EnumerableExtension
  def before_each(&tracer)
    vs = each
    Enumerator.new do |y|
      loop do
        v = vs.next
        tracer.call(v)
        y << v
      end
    end
  end

  def after_each(&tracer)
    vs = each
    Enumerator.new do |y|
      loop do
        v = vs.next
        y << v
        tracer.call(v)
      end
    end
  end

  def on_failure(&tracer)
    vs = each
    Enumerator.new do |y|
      v = nil
      begin
        loop do
          v = vs.next
          y << v
          v = nil
        end
      rescue StopIteration
        raise
      rescue
        tracer.call(v)
        raise
      end
    end
  end
end

module Enumerable
  include EnumerableExtension
end

xs = Object.new
def xs.each
  yield 1
  yield 2
  raise RuntimeError, 'bar!'
  yield 3
end

# xs.to_enum.
# [1, 2, 3].to_enum.
[1, 2, 3].
before_each {|x| puts "before #{x}"}.
after_each {|x| puts "success #{x}"}.
on_failure {|x| puts "failure #{x}"}.
each do |x|
  puts "doing #{x}"
  raise RuntimeError, 'foo!' if x == 3
  puts "done #{x}"
end

3_idea_result.txt

YUKI.N> ruby t.rb
t.rb:58:in `<main>': undefined method `before_each' for [1, 2, 3]:Array (NoMethodError)