This is a corecursive algorithm, because with each iteration it calls itself on data that is greater then what it had before: iterate f x = x : iterate f (f x) It is similar to tail recursion ac...

I find that Lazy and Inf is very close: Lazy and Inf are closely related (in fact, the underlying implementation uses the same type). The only difference in practice is in totality checking, w...

There is filter : (a -> Bool) -> List a -> List a for List, but there is no filter : (a -> Bool) -> Stream a -> Stream a for Stream, why? Is there some alternatives to do the sim...

There is some explanation here. Intuitively I understand how finite data structures differ from infinite data structures like streams. Nevertheless, it's interesting to see other explanations of di...

Imagine the following function to give an infinite lazy sequence of fibonacci in Clojure: (def fib-seq (concat [0 1] ((fn rfib [a b] (lazy-cons (+ a b) (rfib b (+ a b)))) 0 1))) user> (tak...

In terms of pithy summaries - this description of Comonads seems to win - describing them as a 'type for input impurity'. What is an equivalent pithy (one-sentence) description for codata?