Allow to unmoemoize only specific method(s)

In this example foo is memoized method ?

Using unmemoize(:method1, :method2) can be useful when we want to override attribute setter which depends on our memoized methods, for AR we can override reload to unmemoize_all, but in such example we clear whole cache, even if we only need to clear one method.

class Foo < ActiveRecord::Base
  extend ActiveSupport::Memoizable

  def is_something_valid?
    if self.only_locations && Location.find(:all, :conditions => ['some_conditions']
       true
    else
       false
    end
  end

  def only_locations=(value)
     unmemoize(:is_something_valid?)
     super(value)
  end

  memoize(:is_something_valid?)
end

Internally in Memoizable::Freezable i think it will be DRY to not repeat same code in unmemoizel_all and unmemoize. Obviously i don't know what internal policy Rails have, and it is really necessary to be DRY fundamentalist here.

You sold me.

A few things though,

1. Needs test case
2. Like you said, build unmemoize_all on top of it. Maybe even make unmemoize_all just unmemoize(:all)
3. I know we'd be changing old apis, but unmemoize isn't intention revealing. It sounds like is doing the opposite of the memoize helper and removing the ability permanently. I'd prefer something like "flush_cache".

I love it ;) Big thanks.