Skip to content
This repository

HTTPS clone URL

Subversion checkout URL

You can clone with HTTPS or Subversion.

Download ZIP

ActiveSupport::Memoizable with a few enhancements

branch: master
README.md

Memoist

Build Status

Memoist is an extraction of ActiveSupport::Memoizable.

Since June 2011 ActiveSupport::Memoizable has been deprecated. But I love it, and so I plan to keep it alive.

Usage

Just extend with the Memoist module

require 'memoist'
class Person
  extend Memoist

  def social_security
    decrypt_social_security
  end
  memoize :social_security
end

And person.social_security will only be calculated once.

Every memoized function (which initially was not accepting any arguments) has a (reload) argument you can pass in to bypass and reset the memoization:

def some_method
  Time.now
end
memoize :some_method

Calling some_method will be memoized, but calling some_method(true) will rememoize each time.

You can even memoize method that takes arguments.

class Person
  def taxes_due(income)
    income * 0.40
  end
  memoize :taxes_due
end

This will only be calculated once per value of income.

You can also memoize class methods.

class Person

  class << self
    extend Memoist
    def with_overdue_taxes
      # ...
    end
    memoize :with_overdue_taxes
  end

end

Reload

Each memoized function comes with a way to flush the existing value.

person.social_security       # returns the memoized value
person.social_security(true) # bypasses the memoized value and rememoizes it

This also works with a memoized method with arguments

person.taxes_due(100_000)       # returns the memoized value
person.taxes_due(100_000, true) # bypasses the memoized value and rememoizes it

If you want to flush the entire memoization cache for an object

person.flush_cache

Authors

Everyone who contributed to it in the rails repository.

  • Joshua Peek
  • Tarmo Tänav
  • Jeremy Kemper
  • Eugene Pimenov
  • Xavier Noria
  • Niels Ganser
  • Carl Lerche & Yehuda Katz
  • jeem
  • Jay Pignata
  • Damien Mathieu
  • José Valim
  • Matthew Rudy Jacobs

Contributing

  1. Fork it ( http://github.com//memoist/fork )
  2. Create your feature branch (git checkout -b my-new-feature)
  3. Commit your changes (git commit -am 'Add some feature')
  4. Push to the branch (git push origin my-new-feature)
  5. Create new Pull Request

License

Released under the MIT License, just as Ruby on Rails is.

Something went wrong with that request. Please try again.