How to design a function like Clojure 'iterate'

[ssqq]

Following code could make a infinite sequence:

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   (define (f)
    (begin
        (println (inc cnt))
        (push (last f) f -1)
        (if (> (length f) 3) (pop f 1))))


But it is not lazy list:

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(first (f)) --> not 1

How to design a infinite sequence just like iterate and take in Clojure.



(take 10 (iterate inc 5))

[rickyboy]

How to design a infinite sequence just like iterate and take in Clojure.



(take 10 (iterate inc 5))

Here you go. :)

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> (sequence 5 14)
(5 6 7 8 9 10 11 12 13 14)

^^ This is just a way of saying, "Why do you want to do that?"  newLISP is inherently eager, and doing such a thing in the most straight-forward way is the best.  Unless, we are not privy to something ...

[ssqq]

richyboy, yes, you are right. I think so.

[cormullion]

http://www.newlispfanclub.alh.net/forum/viewtopic.php?f=16&t=3161&p=17075&hilit=lazy#p17075">some previous discussion

[TedWalther]

I would do it using a context to store internal state, each call to the context/function would update the state and return it.  Look at the implementations of gensym on here for ideas.