functional programming

https://subscription.packtpub.com/book/application_development/9781786461483/1/ch01lvl1sec8/principles-of-functional-programming.

https://medium.freecodecamp.org/an-introduction-to-the-basic-principles-of-functional-programming-a2c2a15c84

The following are the CORE principles of FP:

• Immutability

• Disciplined state

• Pure functions and no side effects/disciplined states

• First class functions and high order functions

• Type systems

• Referential transparency