> Clearly interfaces are a crucial aspect of compositionality, and I suspect that interfaces are in fact synonymous with compositionality. That is, compositiona

> Clearly interfaces are a crucial aspect of compositionality, and I suspect that interfaces are in fact synonymous with compositionality. That is, compositionality is not just the ability to compose objects, but the ability to work with an object after intentionally forgetting how it was built. Well, it's complicated. Quoting Gerald Sussman from https://wingolog.org/archives/2018/01/11/spectre-and-the-end-of-langsec https://wingolog.org/archives/2018/01/11/spectre-and-the-end... > The work of engineers used to be about taking small parts that they understood entirely and using simple techniques to compose them into larger things that do what they want. > But programming now isn't so much like that. Nowadays you muck around with incomprehensible or nonexistent man pages for software you don't know who wrote. You have to do basic science on your libraries to see how they work, trying out different inputs and seeing how the code reacts. This is a fundamentally different job.