The compute-slots method for <redefinable-class> does a transformation
of #:allocation #:instance slots to #:allocation #:virtual slots, but
in doing so it discards all slot options besides the standard ones.
This means that a metaclass that inherits from <redefinable-class>
won't work as expected if it relies upon custom slot options.
Test case:
(use-modules (oop goops)
(srfi srfi-111))
(define-class <meta> (<class>))
(define (boxed-slot? slot)
(get-keyword #:box? (slot-definition-options slot)))
(define-method (compute-getter-method (class <meta>) slot)
(if (boxed-slot? slot)
(make <method>
#:specializers (list class)
#:procedure (let ((slot-name (slot-definition-name slot)))
(lambda (obj)
(unbox (slot-ref obj slot-name)))))
(next-method)))
(define-method (compute-setter-method (class <meta>) slot)
(if (boxed-slot? slot)
(make <method>
#:specializers (list class <top>)
#:procedure (let ((slot-name (slot-definition-name slot)))
(lambda (obj value)
(set-box! (slot-ref obj slot-name) value))))
(next-method)))
(define-class <redefinable-meta> (<meta> <redefinable-class>))
(define-class <foo> ()
(bar #:accessor bar #:box? #t #:init-form (box 123))
#:metaclass <meta>)
(define-class <redefinable-foo> ()
(bar #:accessor bar #:box? #t #:init-form (box 123))
#:metaclass <redefinable-meta>)
;; This works:
(pk (+ (bar (make <foo>)) 456))
;; This throws an error:
(pk (+ (bar (make <redefinable-foo>)) 456))
Attached is a patch that preserves all slot options that redefinable
classes do not need to alter, including custom ones. How does it
look?
- Dave
0001-goops-Preserve-all-slot-options-in-redefinable-class.patch
Description: Text Data
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