_p_ tapp is tap and p, _p_ is an alias of tapp. Installation gem install _p_ or in Gemfile: gem "_p_" Usage >> require '_p_' => true >> (1..5)._p_.select(&:odd?)._p_.inject(&:+) 1..5 [1, 3, 5] => 9 See also: https://github.com/esminc/tapp