diff options
Diffstat (limited to 'activesupport/lib/active_support/memoizable.rb')
-rw-r--r-- | activesupport/lib/active_support/memoizable.rb | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/activesupport/lib/active_support/memoizable.rb b/activesupport/lib/active_support/memoizable.rb new file mode 100644 index 0000000000..d06250171a --- /dev/null +++ b/activesupport/lib/active_support/memoizable.rb @@ -0,0 +1,35 @@ +module ActiveSupport + module Memoizable + def self.included(base) #:nodoc: + base.extend(ClassMethods) + end + + module ClassMethods + def memoize(symbol) + original_method = "_unmemoized_#{symbol}" + memoized_ivar = "@_memoized_#{symbol}" + raise "Already memoized #{symbol}" if instance_methods.map(&:to_s).include?(original_method) + + alias_method original_method, symbol + class_eval <<-EOS, __FILE__, __LINE__ + def #{symbol} + if defined? #{memoized_ivar} + #{memoized_ivar} + else + #{memoized_ivar} = #{original_method} + end + end + EOS + end + end + + def freeze + methods.each do |method| + if m = method.to_s.match(/\A_unmemoized_(.*)/) + send(m[1]).freeze + end + end + super + end + end +end |