return.rb

class A
  def implicit_block_implicit_ensure
    begin
      "block"
    ensure
      "ensure"
    end
  end

  def implicit_block_explicit_ensure
    begin
      "block"
    ensure
      return "ensure"
    end
  end

  def explicit_block_implicit_ensure
    begin
      return "block"
    ensure 
      "ensure"
    end
  end

  def explicit_block_explicit_ensure
    begin
      return "block"
    ensure
      return "ensure"
    end
  end

  def empty_block_implicit_ensure
    begin
    ensure
      "ensure"
    end
  end
end

methods = A.new.methods - Object.new.methods

methods.sort.each do |m|
  a = A.new
  puts "#{m} -> #{a.send( m ).inspect}"
end

for the lazy (on 1.8.7)

empty_block_implicit_ensure -> nil
explicit_block_explicit_ensure -> "ensure"
explicit_block_implicit_ensure -> "block"
implicit_block_explicit_ensure -> "ensure"
implicit_block_implicit_ensure -> "block"