Details
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Type:
Defect
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Status:
Open
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Priority:
Minor
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Resolution: Unresolved
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Affects Version/s: Release 1.4
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Fix Version/s: None
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Component/s: None
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Labels:None
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Environment:Ubuntu, lein 1.7.1 - lein repl
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Approval:Vetted
Description
In lein 1.7.1 (and CCW) the form (def ^{:type :anything} mydef 1) throws "ClassCastException clojure.lang.Var cannot be cast to clojure.lang.IObj clojure.core/with-meta (core.clj:211)".
This seems to be due to setting the :type metadata. With other metadata keys it works well.
If it is intended to forbid setting the :type metadata, then there should be an appropriate error message instead of the ClassCastException
In lein2 repl which is using "REPL-y 0.1.0-beta8" the exception does not occur.
Full stacktrace:
java.lang.ClassCastException: clojure.lang.Var cannot be cast to clojure.lang.IObj
at clojure.core$with_meta.invoke (core.clj:211)
clojure.core$vary_meta.doInvoke (core.clj:617)
clojure.lang.RestFn.invoke (RestFn.java:425)
clojure.core/fn (core_print.clj:76)
clojure.lang.MultiFn.invoke (MultiFn.java:167)
clojure.core$pr_on.invoke (core.clj:3266)
clojure.core$pr.invoke (core.clj:3278)
clojure.lang.AFn.applyToHelper (AFn.java:161)
clojure.lang.RestFn.applyTo (RestFn.java:132)
clojure.core$apply.invoke (core.clj:601)
clojure.core$prn.doInvoke (core.clj:3311)
clojure.lang.RestFn.invoke (RestFn.java:408)
clojure.main$repl$read_eval_print__6405.invoke (main.clj:246)
clojure.main$repl$fn__6410.invoke (main.clj:266)
clojure.main$repl.doInvoke (main.clj:266)
clojure.lang.RestFn.invoke (RestFn.java:512)
user$eval27$acc_3261auto__30$fn_32.invoke (NO_SOURCE_FILE:1)
clojure.lang.AFn.run (AFn.java:24)
java.lang.Thread.run (Thread.java:662)
This is caused by the printer dispatch function
(defmulti print-method (fn [x writer] (let [t (get (meta x) :type)] (if (keyword? t) t (class x)))))which ends up calling the default dispatch, which tries to vary-meta.
(defmulti print-method (fn [x writer] (let [t (get (meta x) :type)] (if (keyword? t) t (class x)))))