Code Reuse Without Classes: A Deep Dive into Non-OOP Reusability

In the grand narrative of software development, Object-Oriented Programming (OOP) is often cast as the protagonist of reusability. We’re taught that through encapsulation, inheritance, and polymorphism, we can build modular, Lego-like systems that are easy to extend and maintain. And for many decades, this story has held true. The class, the object, the interface — these are the bedrock concepts upon which vast digital empires have been built.

But this narrative, compelling as it is, is incomplete. It risks overshadowing other, equally powerful — and in some contexts, superior — paradigms for achieving the holy grail of software engineering: writing code once and using it everywhere. The idea that reusability is exclusively, or even primarily, the domain of OOP is a misconception. From the stark simplicity of the 1970s Unix command line to the mind-bending elegance of modern functional and generic programming, brilliant minds have been solving the reusability puzzle in ways that have nothing to do with new keywords or class hierarchies.

This article is an exploration of that hidden world. We will journey through five distinct yet interconnected philosophies that have achieved tremendous reusability without relying on traditional object-oriented principles. We’ll see how composing tiny programs, treating…