14.1.proc_example.rb

def dividers
  puts ''
  puts '++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++'
  puts '  Next Example'
  puts '++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++'
  puts ''
end

def do_self_importantly some_proc
  puts "Everybody just HOLD ON! I'm doing something..."
  some_proc.call
  puts "OK everyone, I'm done. As you were."
end

say_hello = Proc.new do
  puts 'hello'
end

do_self_importantly say_hello

dividers
puts 'Proc example extended.'

do_you_like = Proc.new do |good_stuff|
  puts "I *really* like #{good_stuff}"
end

do_you_like.call 'chocolate'
do_you_like.call 'Ruby'

dividers
puts 'Proc example extended.'

def do_until_false first_input, some_proc
  input = first_input
  output = first_input

  while output
    input = output
    output = some_proc.call input
  end

  input
end

build_array_of_squares = Proc.new do |array|
  last_number = array.last
  if last_number <= 0
    false
  else
    # Take off the last number...
    array.pop
    # ... and replace it with its square...
    array.push last_number * last_number
    # ...followed by the next smaller number.
    array.push last_number - 1
  end
end

always_false = Proc.new do |just_ignore_me|
  false
end

puts do_until_false([5], build_array_of_squares).inspect

yum = 'lemonade with a hint of orange blossom water'
puts do_until_false(yum, always_false)