What is tail recursion?

Question

Whilst starting to learn lisp, I\'ve come across the term tail-recursive. What does it mean exactly?

Answer 1

There are two basic kinds of recursions: head recursion and tail recursion.

In head recursion, a function makes its recursive call and then performs some more calculations, maybe using the result of the recursive call, for example.

In a tail recursive function, all calculations happen first and the recursive call is the last thing that happens.

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