R devel - Dec 2025 - non-API SETLENGTH and friends will be dropped soon

As part of clarifying and tightening the R API for packages the
non-API entry points SETLENGTH, TRUELENGTH, SET_TRUELENGTH, and
SET_GROWABLE_BIT will be removed from installed header files and,
where possible, hidden from package access. The first step will be to
turn current check NOTEs into WARNINGs; this will hopefully happen in
the next few weeks. Hopefully the process can be completed by early
January.

17 CRAN/BIOC packages currently make use of one or more of these entry
points. Most using SETLENGTH should transition to using xgetlength(),
which allocates a new vector, usually with a shorter length. There is
a small amount of overhead, and care is needed to protect the new
result, but this is a much safer option. R-devel does now include an
experimental API for creating resizable vectors, but it needs a great
deal of care to use safely. These options are described in a new
section "Resizing vectors" in the Writing R Extensions manual.

[If you are a maintainer of one of the 17 affected packages you should
receive a separate copy of this note.]

Best,

luke
~

-- 
Luke Tierney
Ralph E. Wareham Professor of Mathematical Sciences
University of Iowa                  Phone:             319-335-3386
Department of Statistics and        Fax:               319-335-3017
    Actuarial Science
241 Schaeffer Hall                  email:   luke-tierney at uiowa.edu
Iowa City, IA 52242                 WWW:  http://www.stat.uiowa.edu

Dear Luke,

I have implemented changes knowing this was around the corner to address this
and hopefully can finalize unit tests/comparisons in the next week (I also want
to take a look at the new resizable option to see how that compares to what I
did), but it looks like CRAN will be down for submissions from Dec 23 through
Jan 7.   Hoping the grace period takes into account this down time in case early
submissions fail on some of the CRAN machines despite all efforts to test ahead
of time.

Best,
Merlise

From: luke-tierney at uiowa.edu <luke-tierney at uiowa.edu>
Date: Wednesday, December 3, 2025 at 8:47?PM
To: R-devel at r-project.org <R-devel at r-project.org>
Subject: non-API SETLENGTH and friends will be dropped soon

As part of clarifying and tightening the R API for packages the
non-API entry points SETLENGTH, TRUELENGTH, SET_TRUELENGTH, and
SET_GROWABLE_BIT will be removed from installed header files and,
where possible, hidden from package access. The first step will be to
turn current check NOTEs into WARNINGs; this will hopefully happen in
the next few weeks. Hopefully the process can be completed by early
January.

17 CRAN/BIOC packages currently make use of one or more of these entry
points. Most using SETLENGTH should transition to using xgetlength(),
which allocates a new vector, usually with a shorter length. There is
a small amount of overhead, and care is needed to protect the new
result, but this is a much safer option. R-devel does now include an
experimental API for creating resizable vectors, but it needs a great
deal of care to use safely. These options are described in a new
section "Resizing vectors" in the Writing R Extensions manual.

[If you are a maintainer of one of the 17 affected packages you should
receive a separate copy of this note.]

Best,

luke
~

--
Luke Tierney
Ralph E. Wareham Professor of Mathematical Sciences
University of Iowa                  Phone:             319-335-3386
Department of Statistics and        Fax:               319-335-3017
    Actuarial Science
241 Schaeffer Hall                  email:   luke-tierney at uiowa.edu
Iowa City, IA 52242                 WWW: 
http://www.stat.uiowa.edu/<http://www.stat.uiowa.edu/>

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