final edits

Author: paleolimbot

r/R/vctr.R

@@ -29,7 +29,7 @@
 #' storage type is an `integer()` that is a sequence along the total length
 #' of the vctr and there are attributes that are required to resolve these
 #' indices to an array + offset. Sequences typically have a very compact
-#' representation in recent version of R such that this has a cheap storage
+#' representation in recent versions of R such that this has a cheap storage
 #' footprint even for large arrays. The attributes are currently:
 #'
 #' - `schema`: The [nanoarrow_schema][as_nanoarrow_schema] shared by each chunk.

r/man/as_nanoarrow_vctr.Rd

@@ -20,6 +20,7 @@
 #include <Rinternals.h>
 
 #include "nanoarrow.h"
+#include "nanoarrow/r.h"
 
 SEXP nanoarrow_c_vctr_chunk_offsets(SEXP array_list) {
   int num_chunks = Rf_length(array_list);
@@ -30,7 +31,7 @@ SEXP nanoarrow_c_vctr_chunk_offsets(SEXP array_list) {
 
   struct ArrowArray* array;
   for (int i = 0; i < num_chunks; i++) {
-    array = (struct ArrowArray*)R_ExternalPtrAddr(VECTOR_ELT(array_list, i));
+    array = nanoarrow_array_from_xptr(VECTOR_ELT(array_list, i));
     cumulative_offset += array->length;
     if (cumulative_offset > INT_MAX) {
       Rf_error("Can't build nanoarrow_vctr with length > INT_MAX");  // # nocov
@@ -90,6 +91,10 @@ SEXP nanoarrow_c_vctr_as_slice(SEXP indices_sexp) {
     return slice_sexp;
   }
 
+  // It may be possible to check for the R ALTREP sequence type,
+  // which would eliminate the need for the below check for
+  // sequential values.
+
   int buf[1024];
   INTEGER_GET_REGION(indices_sexp, 0, 1024, buf);
   slice[0] = buf[0];

r/src/vctr.c

@@ -177,7 +177,7 @@ test_that("convert to vector works for nanoarrow_vctr()", {
   schema <- infer_nanoarrow_schema(vctr)
   expect_identical(schema$format, "u")
 
-  # Check nested conversion from a data.frame
+  # Check conversion of a struct array
   df <- data.frame(x = c("one", "two", "three"))
   array <- as_nanoarrow_array(df)
 
@@ -187,7 +187,6 @@ test_that("convert to vector works for nanoarrow_vctr()", {
   schema <- infer_nanoarrow_schema(vctr)
   expect_identical(schema$format, "+s")
 
-
   vctr <- convert_array(array, nanoarrow_vctr(na_struct(list(x = na_string()))))
   expect_s3_class(vctr, "nanoarrow_vctr")
   expect_length(vctr, 3)