gistfile1.clj

;; Does core.type intersection not work on values?

(ns user-types.demo
  (:require [clojure.core.typed :as t]))

(t/defalias week-days "mon-fri"
  (t/U (t/Val :mon) (t/Val :tue) (t/Val :wed) 
       (t/Val :thu) (t/Val :fri) ))

(t/defalias party-days "days with party events"
  (t/U  (t/Val :fri) (t/Val :sat)))

(t/defalias party-days-of-the-week "days in the week with party events"
  (t/I week-days party-days))

(t/defn party-during-week [x :- party-days-of-the-week] x)

;; then in repl
(check-ns 'user-types.demo)

(t/cf (u/party-during-week :wed))
;; ups, no error? only friday should be allowed
=> [(t/I u/party-days u/week-days) {:then tt, :else ff}]

Looks like a bug. http://dev.clojure.org/jira/browse/CTYP-225