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[!?=]$/
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)
value.unshift block if block
@#{ name } = value.first
end
"
module_eval " def #{ name }(*value, &block)
value.unshift block if block
return self.send('#{ name }=', value.first) unless value.empty?
#{ name }! unless defined? @#{ name }
@#{ name }
end
"
module_eval " def #{ name }!
initializer = ObjectSpace._id2ref #{ initializer_id }
self.#{ name } = initializer.call(self)
@#{ name }
end
"
module_eval " def #{ name }?
#{ name }
end
"
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