Functional Recursion

Do tail recursion without overflowing with generators and functions.

Why?

I am coming from a background of functional programming languages where loops are not standard. Instead, recursion is used to achieve the same result more succinctly.

Overview

It provides:

• Infinite recursion with return
• Infinite recursion with generators (yield)

Using this has the following advantages:

• Allows for more understandable code given the right situation
• Avoid bugs because of deeply nested loops

Instructions

Run in the console

python3 -m pip install functional_recursion

(Use python or python3 depending on your environment)

And to use it

from functional_recursion import recur, recur_yield, tail_recursive, tail_recursive_yield

@tail_recursive
def fib_decorator_recursive(n, last_two=None):
    if last_two is None:
        last_two = (0, 1)
    if n == 0:
        return last_two[1]
    last_two = (last_two[1], sum(last_two))
    return recur(n - 1, last_two)


@tail_recursive_yield
def fib_decorator_recursive_generator(last_two=None):
    if last_two is None:
        last_two = (0, 1)
    last_two = (last_two[1], sum(last_two))
    return recur_yield(last_two, yield_val=last_two[0])

* See the complete examples and performance times here.

Authors

• Hunter Wilhelm