I don't see how it would be gatekeeping.

Recursive functions are a mathematical concept, like the "imaginary" number, or "trascendental" numbers. Or negative numbers for that matter.

Simple example, the Fibonacci sequence. FIB(1) = 1 FIB(2) = 1 FIB(N) = FIB(N-1) + FIB(N-2)

There's no programming language or "physical" implementation needed in order to calculate FIB(N) for arbitrary N. Pencil and paper will do for small numbers

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fellowniusmonk 4 days ago | parent [-]

Yes, you cannot hide the callstack when taught with pencil and paper.

But in computer programing it is often hidden.

And then you are misleading people about recursion and not helping them to build mental models that map to the physical/hardware process.

This isn't a big deal or anything, it's hardly worth talking about but it is literally a true thing many don't realize and that does empirically negatively effect education of the concept.

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SJC_Hacker 4 days ago | parent [-]

> Yes, you cannot hide the callstack when taught with pencil and paper.

Recursive functions were mathematically defined well before the callstack or the von Neumann architecture was a thing. Godel, Church and Kleene did alot of work on them in the 1930s (and I believe even prior to that infinite series were defined recursively although functional theory had not be worked out), this was before ENIAC (1945) which would be just barely recognizable as a general purpose computer and didn't have anything like CALL instruction.

So I don't understand this notion of "hiding the callstack" comes from. If one cannot understand recursion without invoking the callstack, well thats just them. But I don't see how its absolutely necessary or some universal

	▲	fellowniusmonk 4 days ago \| parent [-]
		I have no complaints about how recursion is taught in mathematics courses. I'm being quite clear that I take issue with how the concept has been taught in many programming books and courses. You can see the ignorance and confusion in this very thread.