### Memoizing in Ruby

Memoization is the pattern of calculating a value once, and re-using that value each subsequent time it is needed. It’s common to encounter this in Ruby in the form @variable ||= calculation. It’s so common that it is often used even where it’s not expensive or re-used; it’s become a part of idiomatic Ruby. In my last post I made an off-hand reference to solving the problem of using memoization for falsy values, and it seems a topic worth talking about in and of itself.