Nested seqs in clojure.spec

Question

When I use clojure.spec, I am trying to figure out how to spec nested seq/vector. Here is my failing example:

(s/def ::test (s/cat :s any? :r (s/cat :int int?)))
(s/explain-str ::test ["test" [1]])
;; => "[1] - failed: int? in: [1] at: [:r :int] spec: :ct.biz.ext2-test/test\n"

As you can see it fails on [1] being explained against int?. Why not against (s/cat :int int?)? It looks like it's actually flattening the spec, which was mentioned in some note somewhere. But how would I correctly spec my data?

Answer 1

s/cat is a regular expression. So it will match all expression that fit. s/spec allows to create a nested spec. So the correct spec for above is:

(s/cat :any any? :r (s/spec (s/cat int int?)))