CODEWITHSUNDEEP
filterscheme
WorBlux
WorBlux

Reputation: 1413

Mit-scheme, recursion error with built-in filter function

(filter even? (numb-2tx 100000))

;Aborting!: maximum recursion depth exceeded
;;numb-2tx generates a list from 2 to x, even for very large values of x (tested with 2000000)

When I try to apply the filter function to very long lists (>40,000 or so) I run into the maximum recursion depth error.

Is there a similar built-in that doesn't run into this problem, or will I have to come up with a tail-recursive equivalent on my own?

Upvotes: 0

Views: 991

Answers (1)

GoZoner
GoZoner

Reputation: 70145

Start MIT Scheme with the --stack option. Like this:

$ mit-scheme --stack 10000

Here was my result with the out-of-the-box stack and also with a stack of 1000:

> (length (filter even? (iota 1000000)))

;Aborting!: maximum recursion depth exceeded

Then, after using --stack 10000:

> (length (filter even? (iota 1000000)))

;Value: 500000

It is somewhat disturbing to know that filter has this apparently non-tail-recursive behavior.

Upvotes: 1

Related Questions