Contents

require 'protocol/core'

class Person
  def initialize(name, size)
    @name, @size = name, size
  end

  attr_reader :name, :size

  def <=>(other)
    size <=> other.size
  end

  conform_to Comparing
end

goliath = Person.new 'Goliath', 2_60
david = Person.new 'David', 1_40
symbol = Person.new 'The artist formerly known as Prince', 1_40

david < goliath   # => true
david >= goliath  # => false
david == symbol   # => true

begin
  class NoPerson
    def initialize(name, size)
      @name, @size = name, size
    end

    attr_reader :name, :size

    conform_to Comparing
  end
rescue Protocol::CheckFailed => e
  e.to_s # => "Comparing#<=>(1): method '<=>' not implemented in NoPerson"
end

Version data entries

3 entries across 3 versions & 1 rubygems

Version	Path
protocol-0.8.2	examples/comparing.rb
protocol-0.8.0	examples/comparing.rb
protocol-0.8.1	examples/comparing.rb