bounds_bug.clj

(ns typed-example.core
  (:import (clojure.lang Symbol Seqable))
  (:require [clojure.core.typed :refer [ann check-ns defprotocol> ann-datatype ann-protocol inst]]))

(ann-protocol Similar
              is-similar? [Similar Any -> Boolean])
(defprotocol> Similar
  (is-similar? [this a]))

(ann-datatype MyInt [x :- Number])
(deftype MyInt [x]
  Similar
  (is-similar? [this m]
    (= x m)))

(ann find-similar (All [[t :< Similar]] 
                    [t (U nil (Seqable t)) -> Boolean]))
(defn find-similar [a as]
  (cond
    (empty? as) false
    (is-similar? a (first as)) true
    :else ((inst find-similar t) a (next as))))
;AssertionError Assert failed: 22: Manually instantiated type t is not between bounds Nothing and typed-example.core/Similar
;(and (sub/subtype? ty upper-bound) (sub/subtype? lower-bound ty))  clojure.core.typed.inst/manual-inst (inst.clj:54)