Introduction

Some features of the language

To get this to work I downloaded scala and intellij.

Functional Programming

Some definitions

Immutability is when we can not allowed to change a variable. Not changing a value means parallelism will work better
Expression are something yields a value. e.g. x+y and have not side effects
Statements is code which does something. e.g. do(something) and have side effects
Function is a a relation between a set of inputs and a set of outputs with the property that each input is related to exactly one output.
- Pure always has the same output, easier to test, parallelisation
- Impure may not have the same output
High Order Functions are function which take functions as an argument

High Order functions allow you to provide some of the method as an argument to extract the part which is different

def getFruits(basket: List[Fruilt], filterByFruit: Fruit => Boolean) = for (fruit <- basket if filterByFruit(fruit)) yield fruit