Scheme Request for Implementation 254,
"Guardians",
by Marc Nieper-Wißkirchen,
is now available for discussion.

SRFI 254 is a fork of SRFI 246, which has now been withdrawn.  SRFI 246 was withdrawn by the editor because there had been no progress since 12-2023, and because he hadn't been able to reach the author since 5-2024. Marc Nieper-Wißkirchen has volunteered to take over, but because he was not a co-author, SRFI 254 was forked from SRFI 246.  We thank John Cowan for SRFI 246 and so much other Scheme work, including many other SRFIs.  Thank you to Marc for taking over this SRFI, and for doing so much other Scheme work, too.

Its draft and an archive of the ongoing discussion are available at https://srfi.schemers.org/srfi-254/.

You can join the discussion of the draft by filling out the subscription form on that page.

You can contribute a message to the discussion by sending it to xxxxxx@srfi.schemers.org.

Here's the abstract:

Guardians allow programs to protect objects from deallocation by the garbage collector and to determine which objects would otherwise have been deallocated. When the object has associated non-memory resources, a program can register it with a guardian. The GC will mark inaccessible objects but will not collect them; at the program's convenience, inaccessible objects are removed from the guardian and their non-memory resources are disposed of. Guardians allow objects to be saved from deallocation indefinitely so that they can be reused or so that clean-up or other actions can be performed using the data stored within the objects. Guardians avoid the problems associated with classical finalizers detailed in the Rationale section.

Regards,

SRFI Editor