Add .size and .error_call to vec_interleave()

NEWS.md

@@ -1,5 +1,9 @@
 # vctrs (development version)
 
+* `vec_interleave()` gains new `.size` and `.error_call` arguments.
+
+* `vec_interleave()` now reports the correct index in errors when `NULL`s are present.
+
 * New `list_combine()` for combining a list of vectors together according to a set of `indices`. We now recommend using:
 
   * `list_combine(x, indices = indices, size = size)` over `list_unchop(x, indices = indices)`

R/slice-interleave.R

@@ -15,12 +15,19 @@
 #'
 #' ## vctrs dependencies
 #'
-#' - [list_unchop()]
+#' - [list_combine()]
 #'
 #' @inheritParams vec_c
 #'
-#' @param ... Vectors to interleave. These will be
-#'   [recycled][theory-faq-recycling] to a common size.
+#' @param ... Vectors to interleave.
+#'
+#' @param .size The expected size of each vector. If not provided, computed
+#'   automatically by [vec_size_common()]. Each vector will be
+#'   [recycled][theory-faq-recycling] to this size.
+#'
+#' @param .ptype The expected type of each vector. If not provided, computed
+#'   automatically by [vec_ptype_common()]. Each vector will be
+#'   [cast][theory-faq-coercion] to this type.
 #'
 #' @export
 #' @examples
@@ -35,8 +42,15 @@
 #' y <- data_frame(x = 3:4, y = c("c", "d"))
 #'
 #' vec_interleave(x, y)
+#'
+#' # `.size` can be used to recycle size 1 elements before interleaving
+#' vec_interleave(1, 2, .size = 3)
+#'
+#' # `.ptype` can be used to enforce a particular type
+#' typeof(vec_interleave(1, 2, .ptype = integer()))
 vec_interleave <- function(
   ...,
+  .size = NULL,
   .ptype = NULL,
   .name_spec = NULL,
   .name_repair = c(
@@ -46,34 +60,48 @@ vec_interleave <- function(
     "universal",
     "unique_quiet",
     "universal_quiet"
-  )
+  ),
+  .error_call = current_env()
 ) {
-  args <- list2(...)
-
-  # `NULL`s must be dropped up front to generate appropriate indices
-  if (vec_any_missing(args)) {
-    missing <- vec_detect_missing(args)
-    args <- vec_slice(args, !missing)
-  }
-
-  n <- length(args)
-  size <- vec_size_common(!!!args)
-
-  indices <- vec_interleave_indices(n, size)
-
-  # TODO: Consider switching to `list_combine()`, add tests for empty `...`
-  # case, which would start returning `unspecified()` rather than `NULL`.
-  # This would be more correct and good for composibility, see
-  # https://github.com/r-lib/vctrs/issues/2055
-  list_unchop(
-    x = args,
-    indices = indices,
+  list_interleave(
+    x = list2(...),
+    size = .size,
     ptype = .ptype,
     name_spec = .name_spec,
-    name_repair = .name_repair
+    name_repair = .name_repair,
+    x_arg = "",
+    error_call = .error_call
   )
 }
 
-vec_interleave_indices <- function(n, size) {
-  .Call(ffi_interleave_indices, n, size)
+# It's sometimes more convenient to supply a list, plus you get access to
+# `x_arg` for better error messages than you get from `vec_interleave(!!!x)`.
+# We could consider exporting this alongside `vec_interleave()`.
+list_interleave <- function(
+  x,
+  ...,
+  size = NULL,
+  ptype = NULL,
+  name_spec = NULL,
+  name_repair = c(
+    "minimal",
+    "unique",
+    "check_unique",
+    "universal",
+    "unique_quiet",
+    "universal_quiet"
+  ),
+  x_arg = caller_arg(x),
+  error_call = current_env()
+) {
+  check_dots_empty0(...)
+  .Call(
+    ffi_list_interleave,
+    x,
+    size,
+    ptype,
+    name_spec,
+    name_repair,
+    environment()
+  )
 }

src/decl/slice-interleave-decl.h

@@ -1 +1,10 @@
-static r_obj* vec_interleave_indices(r_ssize n, r_ssize size);
+static
+r_ssize list_interleave_x_size_used(r_obj* const* v_x, r_ssize x_size);
+
+static
+r_obj* list_interleave_indices(
+  r_obj* const* v_x,
+  r_ssize x_size,
+  r_ssize x_size_used,
+  r_ssize elt_size
+);

src/globals.c

@@ -92,6 +92,7 @@ void vctrs_init_globals(r_obj* ns) {
   INIT_ARG(indices);
   INIT_ARG(sizes);
   INIT_ARG(ptype);
+  INIT_ARG(size);
 
   // Lazy args ---------------------------------------------------------
   INIT_LAZY_ARG_2(dot_name_repair, ".name_repair");

src/globals.h

@@ -69,6 +69,7 @@ struct vec_args {
   struct vctrs_arg* indices;
   struct vctrs_arg* sizes;
   struct vctrs_arg* ptype;
+  struct vctrs_arg* size;
 };
 
 struct lazy_args {

src/init.c

@@ -142,7 +142,7 @@ extern r_obj* vctrs_integer64_proxy(r_obj*);
 extern r_obj* vctrs_integer64_restore(r_obj*);
 extern r_obj* vctrs_list_drop_empty(r_obj*);
 extern r_obj* vctrs_is_altrep(r_obj* x);
-extern r_obj* ffi_interleave_indices(r_obj*, r_obj*);
+extern r_obj* ffi_list_interleave(r_obj*, r_obj*, r_obj*, r_obj*, r_obj*, r_obj*);
 extern r_obj* ffi_compute_nesting_container_info(r_obj*, r_obj*);
 extern r_obj* ffi_locate_matches(r_obj*, r_obj*, r_obj*, r_obj*, r_obj*, r_obj*, r_obj*, r_obj*, r_obj*, r_obj*, r_obj*, r_obj*, r_obj*, r_obj*);
 extern r_obj* ffi_interval_groups(r_obj*, r_obj*, r_obj*, r_obj*);
@@ -343,7 +343,7 @@ static const R_CallMethodDef CallEntries[] = {
   {"vctrs_integer64_restore",                   (DL_FUNC) &vctrs_integer64_restore, 1},
   {"vctrs_list_drop_empty",                     (DL_FUNC) &vctrs_list_drop_empty, 1},
   {"vctrs_is_altrep",                           (DL_FUNC) &vctrs_is_altrep, 1},
-  {"ffi_interleave_indices",                    (DL_FUNC) &ffi_interleave_indices, 2},
+  {"ffi_list_interleave",                       (DL_FUNC) &ffi_list_interleave, 6},
   {"ffi_compute_nesting_container_info",        (DL_FUNC) &ffi_compute_nesting_container_info, 2},
   {"ffi_locate_matches",                        (DL_FUNC) &ffi_locate_matches, 14},
   {"ffi_interval_groups",                       (DL_FUNC) &ffi_interval_groups, 4},