rubyx/lib/register/parfait/meta_class.rb
Torsten Ruger d32b51c67b rename layout to type
this one goes to caleb for pointing it out.
Much better word
2016-02-25 11:50:10 -08:00

69 lines
2.1 KiB
Ruby

module Parfait
# class that acts like a class, but is really the object
# described in the ruby language book as the eigenclass, what you get with
# class MyClass
# class << self <--- this is called the eigenclass, or metaclass, and really is just
# .... the class object but gives us the ability to use the
# syntax as if it were a class
# While the "real" metaclass is the type, we need to honor the constancy of the type
# So the type needs to be copied and replaced anytime it is edited.
# And then changed in the original object, and thus we need this level of indirection
# Basically we implement the Behaviour protocol, by forwarding to the type
class MetaClass < Object
include Logging
attribute :object
def initialize(object)
super()
self.object = object
end
def name
self.object.get_type.name
end
# first part of the protocol is read, just forward to self.object.type
def methods
self.object.get_type.methods
end
def method_names
self.object.get_type.method_names
end
def get_instance_method fname
self.object.get_type.get_instance_method fname
end
def resolve_method m_name
self.object.get_type.resolve_method m_name
end
# the modifying part creates a new type
# forwards the action and replaces the type
def add_instance_method method
type = self.object.get_type.dup
ret = type.add_instance_method(method)
self.object.set_type type
ret
end
def remove_instance_method method_name
type = self.object.get_type.dup
ret = type.remove_instance_method(method_name)
self.object.set_type type
ret
end
def create_instance_method method_name , arguments
raise "create_instance_method #{method_name}.#{method_name.class}" unless method_name.is_a?(Symbol)
log.debug "Add_method: #{method_name} clazz: #{self.name}"
add_instance_method Method.new( self , method_name , arguments )
end
end
end