Schemers,

While porting the SRFI-263 sample implementation to Chicken Scheme I hit two
issues.

(Reference: srfi-263/ subdirectory at
https://github.com/scheme-requests-for-implementation/srfi-263, master as
of 2026-05-23.)

1. delete-slot! calls set-parent-list! with one argument
---------------------------------------------------------

In srfi-263.impl.scm, in delete-slot!, the parent-list cleanup is:

   (if (eq? 'parent (slot-type slot))
       (set-parent-list! (delete (slot-getter slot) parent-list)))

set-parent-list! is the mutator generated by define-record-type for the
object-data record, so it takes (obj-data new-value) — two arguments.
The receiver obj-data is missing.

Under any Scheme that arity-checks record setters this raises at runtime
the first time a parent slot is deleted. Chicken's scrutinizer flagged
it at compile time:

 Procedure `set-parent-list!' is called with 1 argument
 but 2 arguments are expected.

Suggested fix:

   (if (eq? 'parent (slot-type slot))
       (set-parent-list! obj-data
                         (delete (slot-getter slot) parent-list)))

2. srfi-263-syntax library exports symbols the impl does not define
-------------------------------------------------------------------

srfi-263-syntax.scm declares:

   (define-library (srfi 263 syntax)
     (export define-method
             clone-object
             define-object)
     (include "srfi-263-syntax.impl.scm"))

but srfi-263-syntax.impl.scm actually defines:

   set-method!         ; — not define-method
   derive-object
   copy-object         ; — not clone-object
   derive-object/add-slots!
   define-object

So define-method and clone-object are exported names with no binding,
and the macros users actually want (set-method!, derive-object,
copy-object) are not exported at all. An R7RS define-library should
fail to load this.

Suggested fix: either rename the macros to match the declared exports,
or change the export list to match the actual macro names. The bodies
read fine; this looks like a stale export list from an earlier revision.

Aside: the body of test.scm exercises set-method! and derive-object
directly via the impl file include, so the test suite does not currently
detect the missing-export problem.

Derrell