CODEWITHSUNDEEP
scheme
Feng
Feng

Reputation: 2910

Get the first item of filtered list

There is some in clojure, which can be expressed in chicken scheme as following:

(define (some pred coll)
  (lazy-head (lazy-filter pred (list->lazy-seq coll))))

Is there something built-in?

Upvotes: 0

Views: 41

Answers (1)

Alexis King
Alexis King

Reputation: 43842

Take a look at find from SRFI 1—it works just like your implementation:

(find even? '(3 1 4 1 5 9)) ; => 4

Note, however, that is is slightly different from Clojure's some: Clojure returns the value of pred applied to the element, whereas find returns the element itself.

See also any, also from SRFI 1, which is preferable if you don't need the value, just a check for existence.

Upvotes: 3

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