Is there a convention for memoization in a method call?

Question

I want to avoid reevaluation of a value in method call. Untill now, I was doing this:

def some_method
  @some_method ||= begin
    # lot\'s of code
  end
end
         


        

Answer 1

I use the memoist gem, which lets you easily memoize a method without having to alter your original method or create two methods.

So for example, instead of having two methods, file_size and calculate_file_size, and having to implement the memoization yourself with an instance variable:

def file_size
  @file_size ||= calculate_file_size
end

def calculate_file_size
  # code to calculate the file size
end

you can just do this:

def file_size
  # code to calculate the file size
end
memoize :file_size

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

object.file_size       # returns the memoized value
object.file_size(true) # bypasses the memoized value and rememoizes it

So calling object.file_size(true) would be the equivalent of calling object.calculate_file_size...