Fun with Ruby Closures

closures.rb

def aclosure(outer)
  -> (inner) {inner + outer}
end

add3 = aclosure(3)
add10 = aclosure(10)

puts add3.call(5)
puts add10.call(5)

def fill_me_up(num=0, &block)
  puts "Start #{num}..."
  yield(num) if block_given?
  puts '...end'
end

fill_me_up(1)
fill_me_up(2) do |num|
  puts "Some stuff added here!: The Number=#{num}"
end