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cjohansen/protocols.cljs

Created August 31, 2019 07:07
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protocols.cljs
(defprotocol ExtMetaProtocol
:extend-via-metadata true
(ext-meta-protocol [x]))
(ext-meta-protocol (with-meta {} {`ext-meta-protocol (fn [_] 1)})) ;;=> 1
(extend-type clojure.lang.PersistentArrayMap
ExtMetaProtocol
(ext-meta-protocol [m]
2))
(ext-meta-protocol {}) ;;=> 2
(ext-meta-protocol (with-meta {} {`ext-meta-protocol (fn [_] 1)})) ;;=> cljs => 2, clj => 1
@jafingerhut
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Confirmed that Clojure 1.10.1 and ClojureScript 1.10.520 (at least with Node.js runtime) behave differently from each other in the way described above. For cljs the extend-type form must have clojure.lang.PersistentArrayMap replaced with the cljs equivalent cljs.core.PersistentArrayMap.

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