rubyx/lib/vm/meta_class.rb

52 lines
1.9 KiB
Ruby

module Vm
# 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
# PS: can't say i fancy the << self syntax and am considerernig adding a keyword for it, like meta
# In effect it is a very similar construct to def self.function(...)
# So one could write def meta.function(...) and thus define on the meta-class
class MetaClass < ObjectConstant
# no name, nor nothing. as this is just the object really
def initialize(object)
super()
@functions = []
@me_self = object
end
# in a non-booting version this should map to _add_singleton_method
def add_function function
raise "not a function #{function}" unless function.is_a? Function
raise "syserr " unless function.name.is_a? Symbol
@functions << function
end
def get_function name
name = name.to_sym
f = @functions.detect{ |f| f.name == name }
puts "no function for #{name} in Meta #{@me_self.inspect}" unless f
f
end
# way of creating new functions that have not been parsed.
def get_or_create_function name
fun = get_function name
unless fun or name == :Object
supr = @context.object_space.get_or_create_class(@super_class)
fun = supr.get_function name
puts "#{supr.functions.collect(&:name)} for #{name} GOT #{fun.class}" if name == :index_of
end
fun
end
def inspect
"MetaClass on #{@me_self}, #{@functions.length} functions"
end
def to_s
inspect
end
end
end