gistfile1.txt

(ns typingfun.core
  (:require [clojure.core.typed :as t]))

(t/ann-protocol AddProtoc
  adder [AddProtoc Number -> AddProtoc])

(t/defprotocol> AddProtoc
  (adder [this amount]))

(t/ann-datatype Accumulator [t :- Number])

(deftype Accumulator [t]
  AddProtoc
  (adder [_ i] (Accumulator. (+ t i))))

(t/ann t [Number -> Accumulator])
(defn t [i] (Accumulator. i))

(t/ann t2 [Number -> AddProtoc])
(defn t2 [i] (Accumulator. i))

(t/check-ns)

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; IllegalArgumentException Multiple methods in multimethod 'subtype*' match dispatch value: [clojure.core.typed.Protocol clojure.core.typed.Protocol :clojure.core.typed/clojure] -> [clojure.core.typed.Protocol :clojure.core.typed/Type :clojure.core.typed/clojure] and [clojure.core.typed.Protocol clojure.core.typed.Protocol :clojure.core.typed/default], and neither is preferred  clojure.lang.MultiFn.findAndCacheBestMethod (MultiFn.java:136)
;
; Doesn't occur if name of protocol changed to AddProto