On memoization

Summary:

Using “open” recursion:

• We can separate memoization logic from function logic.
• We can memoize functions without modifying the syntax of the function.
• We can make functions generic across multiple types of memoization.

Memoization in Rust.

Consider a recursive function. The most basic example is the Fibonacci sequence. Here is a naive implementation:

fn fib_naive(arg: u32) -> u32 {
    match arg {
        0 => 0,
        1 => 1…