Total programming in Swift – André Videla – Medium

A total program is a program that will never get stuck, crash or run into an infinite loop. It will always terminate correctly in a finite amount of time. If your program is total and is well-typed, then a situation where it crashes or gets stuck cannot exist¹. There are many ways in which a program can be non-total. Here are a few examples:

Source: Total programming in Swift – André Videla – Medium