Three Rules of Three

three-rules-of-three.md

"Three Rules of Three":

1. It is three times as difficult to build reusable components as single use components, and
2. A reusable component should be tried out in three different applications before it will be sufficiently general to accept into a reuse library.
3. Two instances of similar code do not require refactoring, but when similar code is used three times, it should be extracted into a new procedure.

References:

• https://blog.codinghorror.com/rule-of-three/
• https://en.wikipedia.org/wiki/Rule_of_three_(computer_programming)