What Are Partial Applications?

tl;dr;

A Partial Application is a function where some or all of the arguments are packed inside, ready to go and it’s just waiting for a few more before the main function is invoked. They’re like functions that have default arguments, but are pure functions with a fixed amount of parameters.

Introduction

The following article and companion video playlist will cover what a partial application is and how it can be used for a more pure function option for default arguments. It’s assumed you know what pure functions are. We’ll cover:

  • basic function arguments
  • default arguments and how order can make them harder/easier to use
  • function arity
  • function currying with closures and show how the parameter order is reversed compared to default arguments
  • building partial applications to show how to make using default arguments pure
  • creating partial applications with no arguments
Continue reading “What Are Partial Applications?”