gistfile1.rb

require 'yaml'

# yaml-able proc
# write the proc as a string or a block that returns a string
# no bindings!
class Sproc
  def initialize *args, &block
    @proc_string = block_given? ? block.call.to_s : args.first.to_s
  end

  def to_proc
    @proc ||= eval(to_s)
  end

  def to_s
    "Proc.new{ #{@proc_string} }"
  end

  def to_yaml
    @proc = nil
    super
  end

  # passes everything through to the instantiated proc
  # including ``call'' and ``[]''
  def method_missing *args
    to_proc.send *args
  end

end

if __FILE__ == $0

    sproc = Sproc.new(' |n| n * n ')

    sproc[10] == 100 or fail("Bad args.first mojo")
    puts "#{sproc}[10] == 100: passed, from args.first"

    sproc = Sproc.new do
      " |n| n * n "
    end

    sproc[10] == 100 or fail("Bad block mojo")
    puts "#{sproc}[10] == 100: passed, from block"

    YAML::load(sproc.to_yaml)[10] == 100  or fail("Bad yaml mojo")
    puts "YAML::load(sproc.to_yaml)[10] == 100: passed"

    sproc.arity == 1 or fail("Bad pass thru to proc mojo")
    puts "#{sproc}.arity == 1"

    sproc = Sproc.new(' |*args| args.inject(0){|m,n| m + n } ')

    sproc[1,2,3,4,5] == 15 or fail("Bad *args mojo")
    puts "#{sproc}[1,2,3,4,5] == 15: passed"

    sproc.arity == -1 or fail("Bad pass thru to proc mojo")
    puts "#{sproc}.arity == -1: passed"

    puts "Tests passed: #{sproc}, Yay!"

end