`clojure.core/proxy-super`¶

Type: macro Added: Clojure 1.0 Examples: 2 Runnable: 0

([meth & args])

Use to call a superclass method in the body of a proxy method. Note, expansion captures 'this

Examples¶

by juan.facorro on 2012-11-27 . May have evaluation errors.

by BrunoBonacci on 2020-09-30 . May have evaluation errors.

;; WARNING ON REFLECTION:
;; because `proxy-super` expansion captures 'this without type hint,
;; it generates a reflection warning
(set! *warn-on-reflection* true)
true

(def lst (proxy [java.util.ArrayList] []
           (add [x]
             (println "Adding some stuff:" x)
             (proxy-super add x))))
Reflection warning, NO_SOURCE_PATH:4:14 - call to method add can't be resolved (target class is unknown).
#'user/lst

(.add lst 1)
Reflection warning, NO_SOURCE_PATH:1:1 - call to method add can't be resolved (target class is unknown).
Adding some stuff: 1
true

;; In order to avoid the reflection add the type hint to 'this
;; in the following way. Note no reflection warnings.
;; add type to the proxy, add let binding on 'this with type
(def ^java.util.ArrayList lst (proxy [java.util.ArrayList] []
          (add [x]
            (println "Adding some stuff:" x)
            (let [^java.util.ArrayList this this] ;; add explicit type to 'this
              (proxy-super add x)))))
#'user/lst

(.add lst 1)
Adding some stuff: 1
true

Note by glchapman¶

Note that proxy-super calls are not reentrant. If calling the base method results in another call to the virtual method you are overriding (before the proxy-super call has returned), your proxy's code will not be invoked. Instead, the call will go directly to the base class's method.

clojure.core/proxy-super¶

Examples¶

Note by glchapman¶

See also¶

`clojure.core/proxy-super`¶