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From: Per Bothner <>
To: Panicz Maciej Godek <>
Subject: Re: A protected slot is not accessible in a subclass
Date: Fri, 25 Mar 2022 11:46:29 -0700	[thread overview]
Message-ID: <> (raw)
In-Reply-To: <>

On 3/25/22 02:59, Panicz Maciej Godek wrote:
> I tried this:
> (define-simple-class S (gnu.mapping.Symbol)
>     ((*init*)
>      (invoke-special gnu.mapping.Symbol (this) '*init* (("foo":toString):intern) gnu.mapping.Namespace:EmptyNamespace)
>   (set! (field (this) 'name) (("bar":toString):intern))))
> but it gives a similar error:
> java.lang.RuntimeException: no such field name in S
>          at gnu.kawa.reflect.SlotSet.apply(                        at gnu.kawa.reflect.SlotSet.apply3(
>          at S.<init>(tty:14)

This fails because the (set! (field ...) ...) isn't inlined, so we end up using
run-time reflection.  This is a missing Kawa optimization.

Using set-field! instead does work:

  (set-field! (this) 'name (("bar":toString):intern))

Note in this case you need to add:

(import (kawa reflect)) ; for set-field!

I checked in a fix so either of these now work:

  (set! (this):name (("bar":toString):intern))
  (set! name (("bar":toString):intern))

	--Per Bothner

  reply	other threads:[~2022-03-25 18:46 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-03-24 22:14 Panicz Maciej Godek
2022-03-25  4:56 ` Per Bothner
2022-03-25  9:59   ` Panicz Maciej Godek
2022-03-25 18:46     ` Per Bothner [this message]
2022-03-25 20:53       ` Panicz Maciej Godek

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