Equatable

This mixin provides methods of equality based on a single identity method which must return a list of accessors used as the identity keys.

It also provides a "shortcut" for creating the identity method based on given accessors and returns the Equatable module for inclusion. 

  include Equatable(:a, :b)

is equivalent to including a module containing: 

  def ==(other)
    self.a == other.a && self.b == other.b
  end

  def eql?(other)
    self.a.eql?(other.a) && self.b.eql?(other.b)
  end

  def hash()
    self.a.hash ^ self.b.hash
  end
Methods
Public Class methods
identify(base, *accessors)

[ show source ]

# File lib/facets/equatable.rb, line 73
  def self.identify(base, *accessors)
    base.send(:define_method, :identity){ accessors }
    self
  end
Public Instance methods
==(o)

[ show source ]

# File lib/facets/equatable.rb, line 78
  def ==(o)
    identity.all?{ |a| send(a) == o.send(a) }
  end
eql?(o)

[ show source ]

# File lib/facets/equatable.rb, line 82
  def eql?(o)
    identity.all?{ |a| send(a).eql?(o.send(a)) }
  end
hash()

[ show source ]

# File lib/facets/equatable.rb, line 86
  def hash
    identity.inject(0){ |memo, a| memo ^ send(a).hash }
  end