take-while-adjacent.clj

(defn take-while-adjacent
  [f coll]
  (lazy-seq
   (when-let [s (seq coll)]
     (if (f (first s) (second s))
       (cons (first s) (take-while-adjacent f (rest s)))
       (cons (first s) nil)))))


; => (take-while-adjacent not= [1 2 3 3])
; (1 2 3)

; => (take-while-adjacent = [1 1 1 2])
; (1 1 1)

; => (take-while-adjacent square-of [2 4 16 256 100])
; (2 4 16 256)

; => (take-while-adjacent subset-of [1 [1] [[1] [1 2]] [4]])
; (1 [1] [[1] [1 2]])