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What is wrong with this use of rest parameters with defprotocol and defrecord in Clojure?

What is wrong with using the rest options below with defprotocol and defrecord in Clojure?

(defprotocol prot
  (f [this] [this & rest]))

(defrecord rec []
  prot
  (f [this] "one arg")
  (f [this & rest] "more than one arg"))

(prn (f (rec.)))
; (prn (f (rec.) 5))
(prn (f (rec.) 5 6))
; (prn (f (rec.) 5 6 7))

The above code prints the expected result:

"one arg"
"more than one arg"

But if I uncomment any of the commented lines, I get the following exception:

Exception in thread "main" java.lang.IllegalArgumentException: No single method: f of interface: user.prot found for function: f of protocol: prot (bug.clj:10)
    at clojure.lang.Compiler.analyzeSeq(Compiler.java:5376)
    at clojure.lang.Compiler.analyze(Compiler.java:5190)
    at clojure.lang.Compiler.analyze(Compiler.java:5151)
    at clojure.lang.Compiler$InvokeExpr.parse(Compiler.java:3057)
    at clojure.lang.Compiler.analyzeSeq(Compiler.java:5371)
    at clojure.lang.Compiler.analyze(Compiler.java:5190)
    at clojure.lang.Compiler.analyze(Compiler.java:5151)
    at clojure.lang.Compiler$BodyExpr$Parser.parse(Compiler.java:4670)
    at clojure.lang.Compiler$FnMethod.parse(Compiler.java:4328)
    at clojure.lang.Compiler$FnExpr.parse(Compiler.java:3173)
    at clojure.lang.Compiler.analyzeSeq(Compiler.java:5367)
    at clojure.lang.Compiler.analyze(Compiler.java:5190)
    at clojure.lang.Compiler.eval(Compiler.java:5421)
    at clojure.lang.Compiler.load(Compiler.java:5857)
    at clojure.lang.RT.loadResourceScript(RT.java:340)
    at clojure.lang.RT.loadResourceScript(RT.java:327)
    at clojure.lang.RT.loadResourceScript(RT.java:319)
    at clojure.main$load_script.invoke(main.clj:220)
    at clojure.main$script_opt.invoke(main.clj:273)
    at clojure.main$main.doInvoke(main.clj:354)
    at clojure.lang.RestFn.invoke(RestFn.java:409)
    at clojure.lang.Var.invoke(Var.java:365)
    at clojure.lang.AFn.applyToHelper(AFn.java:163)
    at clojure.lang.Var.applyTo(Var.java:482)
    at clojure.main.main(main.java:37)
Caused by: java.lang.IllegalArgumentException: No single method: f of interface: user.prot found for function: f of protocol: prot
    at clojure.lang.Compiler$InvokeExpr.<init>(Compiler.java:2880)
    at clojure.lang.Compiler$InvokeExpr.parse(Compiler.java:3063)
    at clojure.lang.Compiler.analyzeSeq(Compiler.java:5371)
    ... 24 more

Why is this?

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1 answer

As far as I can tell, protocols do not support variable arguments. What is likely to happen is that "&" is understood as an argument character instead of a symbolic indicator / list.

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