;; String-oriented alternative to regular-expression functions in core
(clojure.string/includes? "clojure" "cl")
;;=> true
;; Does *not* work with regular expressions!
(clojure.string/includes? "clojure" #"cl")
;;=> java.util.regex.Pattern cannot be cast to java.lang.CharSequence
;; (java.lang.ClassCastException)