Evaluation count : 4449696 in 6 samples of 741616 calls.
             Execution time mean : 134,589137 ns
    Execution time std-deviation : 13,183541 ns
   Execution time lower quantile : 125,903960 ns ( 2,5%)
   Execution time upper quantile : 156,810049 ns (97,5%)
                   Overhead used : 11,877858 ns

Found 1 outliers in 6 samples (16,6667 %)
  low-severe   1 (16,6667 %)
 Variance from outliers : 30,3177 % Variance is moderately inflated by outliers

(first (filter int? [1 nil nil]))
=> 1
Evaluation count : 17882796 in 6 samples of 2980466 calls.
             Execution time mean : 21,880812 ns
    Execution time std-deviation : 2,182807 ns
   Execution time lower quantile : 20,298050 ns ( 2,5%)
   Execution time upper quantile : 25,304205 ns (97,5%)
                   Overhead used : 11,877858 ns

Found 1 outliers in 6 samples (16,6667 %)
  low-severe   1 (16,6667 %)
 Variance from outliers : 30,4258 % Variance is moderately inflated by outliers

(find-first int? [1 nil nil])
=> 1

Evaluation count : 4502946 in 6 samples of 750491 calls.
             Execution time mean : 150,081691 ns
    Execution time std-deviation : 25,992720 ns
   Execution time lower quantile : 121,161713 ns ( 2,5%)
   Execution time upper quantile : 183,691543 ns (97,5%)
                   Overhead used : 11,877858 ns

(first (filter int? [nil nil 1]))
=> 1
Evaluation count : 7285056 in 6 samples of 1214176 calls.
             Execution time mean : 69,878110 ns
    Execution time std-deviation : 5,317788 ns
   Execution time lower quantile : 65,859802 ns ( 2,5%)
   Execution time upper quantile : 78,592552 ns (97,5%)
                   Overhead used : 11,877858 ns

Found 1 outliers in 6 samples (16,6667 %)
  low-severe   1 (16,6667 %)
 Variance from outliers : 15,4176 % Variance is moderately inflated by outliers

(find-first int? [nil nil 1])
=> 1

(def data (vec (concat (repeat 500 nil) [1])))

(defn tested-by
  "Returns `x` if `(pred x)` is logical true, else `nil`.
   Returns #(tested-by % pred) in case of 1-arity."
  ([pred]
   #(tested-by % pred))
  ([x pred]
   (when (pred x) x)))

(some (tested-by int?) data)