The first example's use case has benefits beyond just shorter code. When writing ruby, I try to code as functionally as possible, and so I built myself a Ruby v

The first example's use case has benefits beyond just shorter code. When writing ruby, I try to code as functionally as possible, and so I built myself a Ruby version of a construct stolen from Lisp, which I use for this exact purpose: def let; yield; end let do |b = ["24 Dec 2011", "23 Jan 2013"].map {|d| Date.parse(d) }| puts "#{b.first} to #{b.last} is #{(b.last - b.first).to_i} days" end --- Unfortunately Ruby's parser doesn't understand multiple assignment and default values in block argument declaration when used simultaneously, so you can't do: let do |(first, last) = ["24 Dec 2011", "23 Jan 2013"].map {|d| Date.parse(d) }| Though you can do this: let do |both = ["24 Dec 2011", "23 Jan 2013"].map {|d| Date.parse(d) }, first = both.first, last = both.last| puts "#{first} to #{last} is #{(last - first).to_i} days"