How would I combine two lists say '(1 2 3 4) and '(:a :b :c :d) to get
(1 :a 2 :b 3 :c 4 :d)
As I can't just do concat as that would add the second list to the end of the first list.
I thought about doing something like
user=> (def a '(1 2 3 4))
user=> (def b '(:a :b :c :d))
user=> (def x (apply conj (second (split-at 1 a)) (nth b 0) (reverse (first (split-at 1 a)))))
(1 :a 2 3 4)
user=> (def y (apply conj (second (split-at 3 x)) (nth b 1) (reverse (first (split-at 3 x)))))
(1 :a 2 :b 3 4)
user=> (def z (apply conj (second (split-at 5 y)) (nth b 2) (reverse (first (split-at 5 y)))))
(1 :a 2 :b 3 :c 4)
user=> (def q (apply conj (second (split-at 7 z)) (nth b 3) (reverse (first (split-at 7 z)))))
(1 :a 2 :b 3 :c 4 :d)
But I think there is a better way
Any help would be much appreciated
An alternative to interleave:
(mapcat list '(1 2 3 4) '(:a :b :c :d))
;;=> (1 :a 2 :b 3 :c 4 :d)
Here mapcat is effectively doing the cat operation after the double map operation has correctly ordered the elements, albeit in list tuples, so '(1 :a) etc.
More explicitly:
(apply concat (map list '(1 2 3 4) '(:a :b :c :d))))
;;=> (1 :a 2 :b 3 :c 4 :d)
Thus if your first list really is increasing integer values then you don't have to generate them:
(apply concat (map-indexed list '(:a :b :c :d)))
;;=> (0 :a 1 :b 2 :c 3 :d)