tap

Yields <code>x</code> to the block, and then returns <code>x</code>. The primary purpose of this method is to "tap into" a method chain, in order to perform operations on intermediate results within the chain.

  (1..10).tap { |x| puts "original: #{x.inspect}" }.to_a.
    tap    { |x| puts "array: #{x.inspect}" }.
    select { |x| x%2 == 0 }.
    tap    { |x| puts "evens: #{x.inspect}" }.
    map    { |x| x*x }.
    tap    { |x| puts "squares: #{x.inspect}" }