def attributes *a, &b
unless a.empty?
returned = Hash.new
hashes, names = a.partition{|x| Hash === x}
names_and_defaults = {}
hashes.each{|h| names_and_defaults.update h}
names.flatten.compact.each{|name| names_and_defaults.update name => nil}
initializers = __attributes__.initializers
names_and_defaults.each do |name, default|
raise NameError, "bad instance variable name '@#{ name }'" if "@#{ name }" =~ %r/[!?=]$/o
name = name.to_s
initialize = b || lambda { default }
initializer = lambda do |this|
Object.instance_method('instance_eval').bind(this).call &initialize
end
initializer_id = initializer.object_id
__attributes__.initializers[name] = initializer
module_eval "def \#{ name }=(*value, &block)\nvalue.unshift block if block\n@\#{ name } = value.first\nend\n"
module_eval "def \#{ name }(*value, &block)\nvalue.unshift block if block\nreturn self.send('\#{ name }=', value.first) unless value.empty?\n\#{ name }! unless defined? @\#{ name }\n@\#{ name }\nend\n"
module_eval "def \#{ name }!\ninitializer = ObjectSpace._id2ref \#{ initializer_id }\nself.\#{ name } = initializer.call(self)\n@\#{ name }\nend\n"
module_eval "def \#{ name }?\n\#{ name }\nend\n"
attributes << name
returned[name] = initializer
end
returned
else
begin
__attribute_list__
rescue NameError
singleton_class =
class << self
self
end
klass = self
singleton_class.module_eval do
attribute_list = List.new
define_method('attribute_list'){ klass == self ? attribute_list : raise(NameError) }
alias_method '__attribute_list__', 'attribute_list'
end
__attribute_list__
end
end
end