Remove arrangements for older versions of R that vroom does not support

MAINTENANCE.md

@@ -28,7 +28,6 @@ The only code path that is multi-threaded is normal files, connections are read
 To compile with logging enabled you need to set `-DVROOM_LOG` in your `~/R/Makevars` and if you want to control the logging level you can set `-DSPDLOG_ACTIVE_LEVEL=SPDLOG_LEVEL_DEBUG`.
 You also need to create the `logs` directory for the logs to be written to. They will write a `logs/index.idx` and a `logs/index_connection.idx` file respectively.
 The file is appended to, not rewritten, so you would need to delete it if you want a new file after a run.
-There is also `-DVROOM_USE_CONNECTIONS_API` to use the CRAN forbidden connections API directly, but the performance difference is generally the same, so it isn't really needed.
 
 ## Known outstanding issues
 
@@ -94,6 +93,14 @@ https://github.com/r-lib/vroom/issues/357 tracks this issue
 The following projects have merit, but would require more maintainer bandwidth than is currently available.
 It is helpful to us to (a) record them explicitly for some possible future and (b) get them out of our open issues.
 
+### Using the Connections API directly
+
+Early in vroom's development, there was the notion that vroom might use the connections API directly.
+But instead of that API becoming more official/public, the opposite happened and it's considered forbidden for a CRAN package to use it.
+In January 2026 in #595, the remaining scaffolding around this was removed, as it had gone unexercised for years.
+
+### Other ideas
+
 * https://github.com/tidyverse/vroom/issues/186
 * https://github.com/tidyverse/vroom/issues/151
 * https://github.com/tidyverse/vroom/issues/250

R/col_types.R

@@ -624,15 +624,11 @@ collector_value.collector_factor <- function(x, ...) {
   factor()
 }
 
-# the more obvious as.POSIXct(double()) doesn't work on R < 4.0
-# https://github.com/tidyverse/vroom/issues/453
 #' @export
 collector_value.collector_datetime <- function(x, ...) {
   vctrs::vec_ptype(Sys.time())
 }
 
-# the more obvious as.Date(double()) doesn't work on R < 4.0
-# and again: https://github.com/tidyverse/vroom/issues/453
 #' @export
 collector_value.collector_date <- function(x, ...) {
   vctrs::vec_ptype(Sys.Date())

R/vroom.R

@@ -479,9 +479,7 @@ vroom_tempfile <- function() {
 #'
 #' Alternatively there is also a family of environment variables to control use of
 #' the Altrep framework. These can then be set in your `.Renviron` file, e.g.
-#' with `usethis::edit_r_environ()`. For versions of R where the Altrep
-#' framework is unavailable (R < 3.5.0) they are automatically turned off and
-#' the variables have no effect. The variables can take one of `true`, `false`,
+#' with `usethis::edit_r_environ()`. The variables can take one of `true`, `false`,
 #' `TRUE`, `FALSE`, `1`, or `0`.
 #'
 #' - `VROOM_USE_ALTREP_NUMERICS` - If set use Altrep for _all_ numeric types
@@ -526,16 +524,16 @@ vroom_altrep <- function(which = NULL) {
   }
 
   args <- list(
-    getRversion() >= "3.5.0" && which$chr %||% vroom_use_altrep_chr(),
-    getRversion() >= "3.5.0" && which$fct %||% vroom_use_altrep_fct(),
-    getRversion() >= "3.5.0" && which$int %||% vroom_use_altrep_int(),
-    getRversion() >= "3.5.0" && which$dbl %||% vroom_use_altrep_dbl(),
-    getRversion() >= "3.5.0" && which$num %||% vroom_use_altrep_num(),
-    getRversion() >= "3.6.0" && which$lgl %||% vroom_use_altrep_lgl(), # logicals only supported in R 3.6.0+
-    getRversion() >= "3.5.0" && which$dttm %||% vroom_use_altrep_dttm(),
-    getRversion() >= "3.5.0" && which$date %||% vroom_use_altrep_date(),
-    getRversion() >= "3.5.0" && which$time %||% vroom_use_altrep_time(),
-    getRversion() >= "3.5.0" && which$big_int %||% vroom_use_altrep_big_int()
+    which$chr %||% vroom_use_altrep_chr(),
+    which$fct %||% vroom_use_altrep_fct(),
+    which$int %||% vroom_use_altrep_int(),
+    which$dbl %||% vroom_use_altrep_dbl(),
+    which$num %||% vroom_use_altrep_num(),
+    which$lgl %||% vroom_use_altrep_lgl(),
+    which$dttm %||% vroom_use_altrep_dttm(),
+    which$date %||% vroom_use_altrep_date(),
+    which$time %||% vroom_use_altrep_time(),
+    which$big_int %||% vroom_use_altrep_big_int()
   )
 
   out <- 0L

README.Rmd

@@ -218,12 +218,10 @@ need to be set by most users.
 - `VROOM_WRITE_BUFFER_LINES` - The number of lines to use for each buffer when
   writing files (default: 1000).
 
-There are also a family of variables to control use of the Altrep framework.
-For versions of R where the Altrep framework is unavailable (R < 3.5.0) they
-are automatically turned off and the variables have no effect. The variables
-can take one of `true`, `false`, `TRUE`, `FALSE`, `1`, or `0`.
+There is also a family of variables to control use of the Altrep framework.
+These variables can take one of these values: `true`, `false`, `TRUE`, `FALSE`, `1`, or `0`.
 
-- `VROOM_USE_ALTREP_NUMERICS` - If set use Altrep for _all_ numeric types
+- `VROOM_USE_ALTREP_NUMERICS` - If true, use Altrep for _all_ numeric types
   (default `false`).
 
 There are also individual variables for each type. Currently only
@@ -240,14 +238,6 @@ There are also individual variables for each type. Currently only
 - `VROOM_USE_ALTREP_DATE`
 - `VROOM_USE_ALTREP_TIME`
 
-## RStudio caveats
-
-RStudio's environment pane calls `object.size()` when it refreshes the pane, which
-for Altrep objects can be extremely slow. RStudio 1.2.1335+ includes the fixes
-([RStudio#4210](https://github.com/rstudio/rstudio/pull/4210),
-[RStudio#4292](https://github.com/rstudio/rstudio/pull/4292)) for this issue,
-so it is recommended you use at least that version.
-
 ## Thanks
 
 - [Gabe Becker](https://github.com/gmbecker), [Luke

README.md

@@ -213,13 +213,11 @@ will not need to be set by most users.
 - `VROOM_WRITE_BUFFER_LINES` - The number of lines to use for each
   buffer when writing files (default: 1000).
 
-There are also a family of variables to control use of the Altrep
-framework. For versions of R where the Altrep framework is unavailable
-(R \< 3.5.0) they are automatically turned off and the variables have no
-effect. The variables can take one of `true`, `false`, `TRUE`, `FALSE`,
-`1`, or `0`.
+There is also a family of variables to control use of the Altrep
+framework. These variables can take one of these values: `true`,
+`false`, `TRUE`, `FALSE`, `1`, or `0`.
 
-- `VROOM_USE_ALTREP_NUMERICS` - If set use Altrep for *all* numeric
+- `VROOM_USE_ALTREP_NUMERICS` - If true, use Altrep for *all* numeric
   types (default `false`).
 
 There are also individual variables for each type. Currently only
@@ -236,15 +234,6 @@ There are also individual variables for each type. Currently only
 - `VROOM_USE_ALTREP_DATE`
 - `VROOM_USE_ALTREP_TIME`
 
-## RStudio caveats
-
-RStudio’s environment pane calls `object.size()` when it refreshes the
-pane, which for Altrep objects can be extremely slow. RStudio 1.2.1335+
-includes the fixes
-([RStudio#4210](https://github.com/rstudio/rstudio/pull/4210),
-[RStudio#4292](https://github.com/rstudio/rstudio/pull/4292)) for this
-issue, so it is recommended you use at least that version.
-
 ## Thanks
 
 - [Gabe Becker](https://github.com/gmbecker), [Luke

src/altrep.cc

@@ -15,7 +15,6 @@
 #include <thread>
 
 [[cpp11::register]] void force_materialization(SEXP x) {
-#ifdef HAS_ALTREP
   // Note: vroom_lgl has no ALTREP implementation, so not included
   if (R_altrep_inherits(x, vroom_chr::class_t)) {
     vroom_chr::Materialize(x);
@@ -36,11 +35,9 @@
   } else if (R_altrep_inherits(x, vroom_big_int::class_t)) {
     vroom_big_int::Materialize(x);
   }
-#endif
 }
 
 bool vroom_altrep(SEXP x) {
-#ifdef HAS_ALTREP
   return R_altrep_inherits(x, vroom_chr::class_t) ||
          R_altrep_inherits(x, vroom_date::class_t) ||
          R_altrep_inherits(x, vroom_dbl::class_t) ||
@@ -51,13 +48,9 @@ bool vroom_altrep(SEXP x) {
          R_altrep_inherits(x, vroom_num::class_t) ||
          R_altrep_inherits(x, vroom_time::class_t) ||
          R_altrep_inherits(x, vroom_big_int::class_t);
-#else
-  return false;
-#endif
 }
 
 [[cpp11::register]] SEXP vroom_materialize(SEXP x, bool replace) {
-#ifdef HAS_ALTREP
   for (R_xlen_t col = 0; col < Rf_xlength(x); ++col) {
     SEXP elt = VECTOR_ELT(x, col);
     if (vroom_altrep(elt)) {
@@ -78,13 +71,10 @@ bool vroom_altrep(SEXP x) {
     }
   }
 
-#endif
-
   return x;
 }
 
 [[cpp11::register]] SEXP vroom_convert(SEXP x) {
-#ifdef HAS_ALTREP
   SEXP out = PROTECT(Rf_allocVector(VECSXP, Rf_xlength(x)));
   SHALLOW_DUPLICATE_ATTRIB(out, x);
 
@@ -137,15 +127,11 @@ bool vroom_altrep(SEXP x) {
   }
   UNPROTECT(1);
   return out;
-#else
-  return x;
-#endif
 }
 
 [[cpp11::register]] std::string vroom_str_(const cpp11::sexp& x) {
   std::stringstream ss;
 
-#ifdef HAS_ALTREP
   if (ALTREP(x)) {
 
     auto csym = CAR(ATTRIB(ALTREP_CLASS(x)));
@@ -160,12 +146,7 @@ bool vroom_altrep(SEXP x) {
       ss << '\t' << "length:" << LENGTH(x);
     }
     ss << '\t' << "materialized:" << materialzied << '\n';
-  }
-#else
-  if (false) {
-  }
-#endif
-  else {
+  } else {
     ss << std::boolalpha << "altrep:" << false << '\t'
        << "type: " << Rf_type2char(TYPEOF(x));
     if (!Rf_isObject(x)) {

src/altrep.h

@@ -2,47 +2,11 @@
 
 #include <R_ext/Rdynload.h>
 
-#if R_VERSION >= R_Version(3, 5, 0)
-#define HAS_ALTREP
-#endif
-
-#ifdef HAS_ALTREP
-#if R_VERSION < R_Version(3, 6, 0)
-
-// workaround because R's <R_ext/Altrep.h> not so conveniently uses `class`
-// as a variable name, and C++ is not happy about that
-//
-// SEXP R_new_altrep(R_altrep_class_t class, SEXP data1, SEXP data2);
-//
-
-// clang-format off
-#ifdef __clang__
-# pragma clang diagnostic push
-# pragma clang diagnostic ignored "-Wkeyword-macro"
-#define class klass
-# pragma clang diagnostic pop
-#else
-#define class klass
-#endif
-// clang-format on
-
-// Because functions declared in <R_ext/Altrep.h> have C linkage
-extern "C" {
-#include <R_ext/Altrep.h>
-}
-
-// undo the workaround
-#undef class
-
-#else
 extern "C" {
 #include <R_ext/Altrep.h>
 }
-#endif
 
 // Backport DATAPTR_RW for R < 4.6.0 (as recommended in Writing R Extensions)
 #if R_VERSION < R_Version(4, 6, 0)
 #define DATAPTR_RW(x) DATAPTR(x)
 #endif
-
-#endif