Memorandum

Memorandum provides a simple method to memoize method results. It also provides flags for freezing the cached results: freeze and deep_freeze.

require 'memorandum'

class Example
  extend Memorandum

  memo def a_method
    puts "Hello from #a_method!"

    rand 'a'..'z'
  end

  memo def another_method n
    puts "Hello from #another_method(#{n.inspect})"

    Array.new(n) { ('a'..'z').to_a.sample }.join
  end

  memo :deep_freeze, def yet_another_method
    {
      child: {
        name: "Memoranda"
      }
    }
  end

  def reset_everything
    memorandum_reset :a_method
    memorandum_reset :another_method
  end
end

example = Example.new

puts example.a_method
puts example.a_method
puts example.another_method 3
puts example.another_method 3
puts example.another_method 5
puts example.another_method 5

example.reset_everything

puts example.a_method
puts example.another_method 3
puts example.another_method 3

Hello from #a_method!
r
r
Hello from #another_method(3)
melg
melg
Hello from #another_method(5)
tmsic
tmsic
x
biel
udihe

Usage

Ruby >= 2.1

memo def the_method arg, another_arg
  'Hello, world'
end

Ruby < 2.1

def the_method
  'Hello, world'
end
memo :the_method

Resetting a Cache

You can reset a method's cached data with #memorandum_reset

class ResetExample
  extend Memorandum

  memo def example_method
    rand
  end

  def reset_some_things
    memorandum_reset :example_method
  end
end

Flags

Flags may optionally be used as arguments before the method name:

memo :freeze, def my_method
  { data: "my data" }
end

Flag	Description
:freeze	Freezes the result
:deep_freeze	Freezes the result and all of it's descendants

Changes

v2.2

• Add #memorandum_reset method

v2.1

• Add :freeze and :deep_freeze flags

v2.0

• New interface

v1.1

• Fix context bug

v1.0

• Initial release