Corecursion

The co- is to indicate that it is opposite of recursion (e.g. sine and cosine).

Let’s say there is an array and you want to sum it up. We can use recursion for it. However, if we want to do the opposite e.g. take a value and generate the array for some reason, that would be corecursion.

Think of implementing the greedy algorithm of the coin change problem: change :: int -> [ int ]

Other names for the same concept:

recursion	corecursion
fold	unfold
catamorphism	anamorphism

https://corecursive.com/046-don-and-adam-folds/

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• Tag: cs