From c152793f2433fd1349906138f661a36d44815bf0 Mon Sep 17 00:00:00 2001
From: aloctavodia <aloctavodia@gmail.com>
Date: Fri, 5 Dec 2025 08:32:33 +0200
Subject: [PATCH 1/4] Use reformulas for formula processing functions

---
 DESCRIPTION               | 3 ++-
 NEWS.md                   | 2 +-
 R/divergence_minimizers.R | 6 +++---
 3 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/DESCRIPTION b/DESCRIPTION
index e7154b4ec..7dd5e80f0 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -56,7 +56,8 @@ Imports:
     MASS,
     ordinal,
     nnet,
-    mclogit
+    mclogit,
+    reformulas,
 Suggests:
     ggrepel,
     ggfortify,
diff --git a/NEWS.md b/NEWS.md
index adca22ad8..6ca8b6572 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -9,7 +9,7 @@ If you read this from a place other than <https://mc-stan.org/projpred/news/inde
 * Added support for censored observations when using the latent projection (with response-scale analyses). This makes it possible, e.g., to use the latent projection for time-to-event models (also known as models for survival analysis). Due to this new feature, the function passed to argument `latent_ll_oscale` of `extend_family()` now needs to have an argument `cens`. See `?extend_family` (section "Latent projection") as well as the latent-projection vignette (section ["Censored observations (survival analysis)"](https://mc-stan.org/projpred/articles/latent.html#cens)) for more information and examples. Note that only the performance statistics `"elpd"`, `"mlpd"`, and `"gmpd"` take censoring into account (on response scale). (GitHub: #528)
 
 ## Minor changes
-
+* Use `reformulas` package directly for formula processing functions. This package is already a dependency of `lme4` >= v1.1-38.
 
 ## Bug fixes
 
diff --git a/R/divergence_minimizers.R b/R/divergence_minimizers.R
index fdd3eae13..5f4bf6a2c 100644
--- a/R/divergence_minimizers.R
+++ b/R/divergence_minimizers.R
@@ -52,7 +52,7 @@ divmin <- function(
     sdivmin <- fit_glmer_callback
     if (getOption("projpred.PQL", FALSE)) {
       # Split up the formula into a fixed and a random part (note: we could also
-      # use lme4::nobars() and lme4::findbars() here):
+      # use reformulas::nobars() and reformulas::findbars() here):
       formula_random <- split_formula_random_gamm4(formula)
       projpred_formulas_no_random <- validate_response_formula(
         formula_random$formula
@@ -1342,11 +1342,11 @@ empty_intersection <- function(x, el_nm = "new") {
 # "GPL (>=2)" (see <https://CRAN.R-project.org/package=lme4>).
 mkNewReTrms_man <- function(re.form, newdata, xlevels, re, D = NULL) {
   stopifnot(!is.null(newdata))
-  tt <- terms(lme4::subbars(re.form))
+  tt <- terms(reformulas::subbars(re.form))
   rfd <- suppressWarnings(
     model.frame(tt, newdata, na.action = na.pass, xlev = xlevels)
   )
-  ReTrms <- lme4::mkReTrms(lme4::findbars(re.form[[2]]), rfd)
+  ReTrms <- reformulas::mkReTrms(reformulas::findbars(re.form[[2]]), rfd)
   ns.re <- names(re)
   nRnms <- names(Rcnms <- ReTrms$cnms)
   if (!all(nRnms %in% ns.re)) {

From d0b17cfa50e0aae2cc63db3b6fd9e45373933e69 Mon Sep 17 00:00:00 2001
From: aloctavodia <aloctavodia@gmail.com>
Date: Fri, 5 Dec 2025 09:02:36 +0200
Subject: [PATCH 2/4] remove warning catching

---
 tests/testthat/test_refmodel.R | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/tests/testthat/test_refmodel.R b/tests/testthat/test_refmodel.R
index e75e58825..fc2f755f4 100644
--- a/tests/testthat/test_refmodel.R
+++ b/tests/testthat/test_refmodel.R
@@ -265,11 +265,6 @@ test_that(paste(
                 weightsnew = wobs_crr,
                 offsetnew = offs_crr,
                 type = "response"),
-        warning = function(w) {
-          if (grepl("nobars.*reformulas", conditionMessage(w))) {
-            invokeRestart("muffleWarning")
-          }
-        }
       ),
       get_warn_wrhs_orhs(tstsetup,
                         weightsnew = wobs_crr,

From 219b6f56bd328c29f720104142e04ab12c4dada2 Mon Sep 17 00:00:00 2001
From: aloctavodia <aloctavodia@gmail.com>
Date: Fri, 5 Dec 2025 09:58:18 +0200
Subject: [PATCH 3/4] fix typo

---
 tests/testthat/test_refmodel.R | 13 ++++---------
 1 file changed, 4 insertions(+), 9 deletions(-)

diff --git a/tests/testthat/test_refmodel.R b/tests/testthat/test_refmodel.R
index fc2f755f4..0c8480974 100644
--- a/tests/testthat/test_refmodel.R
+++ b/tests/testthat/test_refmodel.R
@@ -260,15 +260,10 @@ test_that(paste(
 
     # Without `ynew`:
     expect_warning(
-      predref_resp <- withCallingHandlers(
-        predict(refmods[[tstsetup]], dat,
-                weightsnew = wobs_crr,
-                offsetnew = offs_crr,
-                type = "response"),
-      ),
-      get_warn_wrhs_orhs(tstsetup,
-                        weightsnew = wobs_crr,
-                        offsetnew = offs_crr),
+      predref_resp <- predict(refmods[[tstsetup]], dat, weightsnew = wobs_crr,
+                              offsetnew = offs_crr, type = "response"),
+      get_warn_wrhs_orhs(tstsetup, weightsnew = wobs_crr,
+                         offsetnew = offs_crr),
       info = tstsetup
     )
 

From 2b509ed0c2345fa155da46658d36d54a8a33aadb Mon Sep 17 00:00:00 2001
From: aloctavodia <aloctavodia@gmail.com>
Date: Fri, 5 Dec 2025 10:41:32 +0200
Subject: [PATCH 4/4] expand warn catching

---
 tests/testthat/test_refmodel.R | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/tests/testthat/test_refmodel.R b/tests/testthat/test_refmodel.R
index 0c8480974..6a87083b0 100644
--- a/tests/testthat/test_refmodel.R
+++ b/tests/testthat/test_refmodel.R
@@ -260,8 +260,15 @@ test_that(paste(
 
     # Without `ynew`:
     expect_warning(
-      predref_resp <- predict(refmods[[tstsetup]], dat, weightsnew = wobs_crr,
-                              offsetnew = offs_crr, type = "response"),
+      withCallingHandlers(
+        predref_resp <- predict(refmods[[tstsetup]], dat, weightsnew = wobs_crr,
+                                offsetnew = offs_crr, type = "response"),
+        warning = function(w) {
+          if (grepl("(nobars|subbars|findbars|mkReTrms).*reformulas", conditionMessage(w))) {
+            invokeRestart("muffleWarning")
+          }
+        }
+      ),
       get_warn_wrhs_orhs(tstsetup, weightsnew = wobs_crr,
                          offsetnew = offs_crr),
       info = tstsetup