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UnassignedReporter
Ramsey Nasser
Ramsey NasserLabels
Priority
MinorAffects versions
Created November 13, 2017 at 6:42 PM
Updated March 19, 2018 at 1:30 PM
Resolved March 19, 2018 at 1:30 PM
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MinorMinor
There does not seem to be a consistent way to prevent
deftypefrom emitting a new type. This was discovered in ClojureCLR when trying to write adefonce-style macro wrapper fordeftype, but it affects ClojureJVM as well. It seems to emit types on analysis, which defies Clojure's evaluation semantics.The following REPL session highlights expected and unexpected behavior, namely that
when falseis unable to preventdeftypefrom emitting a new type into memory.commentseems to work, however.nREPL server started on port 52921 on host 127.0.0.1 - nrepl://127.0.0.1:52921 REPL-y 0.3.7, nREPL 0.2.12 Clojure 1.8.0 Java HotSpot(TM) 64-Bit Server VM 1.8.0_60-b27 Docs: (doc function-name-here) (find-doc "part-of-name-here") Source: (source function-name-here) Javadoc: (javadoc java-object-or-class-here) Exit: Control+D or (exit) or (quit) Results: Stored in vars *1, *2, *3, an exception in *e user=> (deftype TypeTest [a b]) user.TypeTest user=> (->> user.TypeTest .getDeclaredFields (map #(.getName %))) ("a" "b") user=> (deftype TypeTest [a b c]) user.TypeTest user=> (->> user.TypeTest .getDeclaredFields (map #(.getName %))) ("a" "b" "c") ;; <= expected redefinition user=> (when false (deftype TypeTest [a])) nil user=> (->> user.TypeTest .getDeclaredFields (map #(.getName %))) ("a") ;; <= when false fails to prevent redefinition user=> (comment (deftype TypeTest [a b c])) nil user=> (->> user.TypeTest .getDeclaredFields (map #(.getName %))) ("a") ;; <= comment manages to prevent redefinition user=>