#+TITLE: functional programming

- functional programming is a way of writing code by means of pure functions
- benefits of functional programming:
  1. Immutability
     - All values derived from old values
  2. Testability
     - Pure functions are easy to test
- difficulties of functional programming:
  1. unintuivive
     - many people learn programming either imperatively or in an
       object-oriented manner
  2. impractical?
     - interfacing with "the real world" is challenging