[kitd]

I hold the view that programming patterns were invented as solutions to technical problems. It was then later that some theoretical "usefulness" or "elegance" was attached to them.

IIRC, there was impetus from Christopher Alexander's architectural "pattern language", and the desire to do something similar in software, which was a bit of an unguided mess at the time.

[Someone]

Simula 67 is (surprise) from 1967, Smalltalk-76 from 1976. Both supported objects and inheritance (http://progopedia.com/language/simula-67/, http://worrydream.com/refs/Ingalls%20-%20The%20Smalltalk-76%...)

“A pattern language” is from 1977; its application to programming from 1987 (http://c2.com/doc/oopsla87.html)

So, in the context of “Simula may have been one of the first to implement inheritance as a means to an end, but how could they have "invented" inheritance?”, I think this discussion is diverging a bit.

I would guess the idea of inheritance was already used in some assembly programs. It would start with people using structures that shared initial fields, and passing them to functions that didn’t care about the other fields (functions handling intrusive linked lists, for example). Passing a pointer to a function that _does_ know the exact type of the fields would be the next step.

The next step would be to allow heterogenous collections and use logic to discern between the various variants (many lisps do that by going through an “is it an atom?, is it a number? etc. chain, and likely did that years before Simula 67 appeared)

Chances are somebody also embedded a function pointer or two inside such objects, but I guess that would have come fairly late, as a function pointer in each object would have been expensive, memory-wise in the ‘60s and ‘70s.

Anyway, I think ‘inheritance’ indeed was invented/discovered, but gradually, and without explicitly naming it.

[js8]

> which was a bit of an unguided mess at the time

Oh, come on. There was https://en.wikipedia.org/wiki/Structured_program_theorem and https://en.wikipedia.org/wiki/Modular_programming. There was a discussion about functional programming, for example famous John Backus article - https://dl.acm.org/doi/pdf/10.1145/359576.359579.

[kitd]

I was really thinking lower-level, specifically OOP, though yes I should've said it. OOP was going to save the world but no one knew how to design properly with it. GoF patterns were a set of off-the-shelf tactical designs intended to get you started in the right direction.