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1.3.0

some

Returns the first logical true value of (pred x) for any x in coll,
else nil. One common idiom is to use a set as pred, for example
this will return :fred if :fred is in the sequence, otherwise nil:
(some #{:fred} coll)

8 Examples top

link | changes
```
user=> (some even? '(1 2 3 4))
true
user=> (some even? '(1 3 5 7))
nil
```
<pre>user=> (some even? '(1 2 3 4)) true user=> (some even? '(1 3 5 7)) nil</pre>
link | changes
```
user=> (some true? [false false false])
nil
user=> (some true? [false true false])
true
user=> (some true? [true true true])
true
```
<pre> user=> (some true? [false false false]) nil user=> (some true? [false true false]) true user=> (some true? [true true true]) true </pre>
link | changes
```
user=> (some #(= 5 %) [1 2 3 4 5])
true
user=> (some #(= 5 %) [6 7 8 9 10])
nil
```
<pre>user=> (some #(= 5 %) [1 2 3 4 5]) true user=> (some #(= 5 %) [6 7 8 9 10]) nil</pre>
link | changes
```
user=> (some #(when (even? %) %) '(1 2 3 4))
2
```
user=> (some #(when (even? %) %) '(1 2 3 4)) 2
link | changes
```
user=> (some {2 "two" 3 "three"} [nil 3 2])
"three"
```
user=> (some {2 "two" 3 "three"} [nil 3 2]) "three"
link | changes
```
;; some can be used as a substitute for (first (filter ...
;; in most cases

user=> (first (filter even? [1 2 3 4]))
2
user=> (some #(if (even? %) %) [1 2 3 4])
2
user=>
```
;; some can be used as a substitute for (first (filter ... ;; in most cases user=> (first (filter even? [1 2 3 4])) 2 user=> (some #(if (even? %) %) [1 2 3 4]) 2 user=>
link | changes
```
;; find a whether a word is in a list of words.
(def word "foo")
(some (partial = word) words)
```
;; find a whether a word is in a list of words. (def word "foo") (some (partial = word) words)
link | changes
```
user=> (some #{2} (range 0 10))
2

user=> (some #{200} (range 0 10))
nil
```
user=> (some #{2} (range 0 10)) 2 user=> (some #{200} (range 0 10)) nil

Source clojure/core.clj:2379 top

(defn some
  "Returns the first logical true value of (pred x) for any x in coll,
  else nil.  One common idiom is to use a set as pred, for example
  this will return :fred if :fred is in the sequence, otherwise nil:
  (some #{:fred} coll)"
  {:added "1.0"
   :static true}
  [pred coll]
    (when (seq coll)
      (or (pred (first coll)) (recur pred (next coll)))))

Vars in clojure.core/some:

Used in 0 other vars

Comments top

1 comment(s) for some.

Sgeo

link

Be careful about using sets as predicates if you don't know what is in the set. In particular,

(#{nil} nil)

nil

and

(#{false} false)

false

Consider using

contains?

instead.