[ARROW-16266] [R] Add StructArray$create()

• Type: Improvement
• Status: In Progress
• Priority: Critical
• Resolution: Unresolved
• Fix Version/s: 11.0.0
• Component/s: R
• Labels: pull-request-available
• External issue URL: https://github.com/apache/arrow/issues/31660
• Assignee: Nicola Crane
• Reporter: Dewey Dunnington
• Created: 21/Apr/22 13:34
• Updated: 11/Jan/23 11:42

Description

In ARROW-13371 we implemented the make_struct compute function bound to data.frame() / tibble() in dplyr evaluation; however, we didn't actually implement StructArray$create(). In ARROW-15168, it turns out that we need to do this to support StructArray creation from data.frames whose columns aren't all convertable using the internal C++ conversion. The hack used in that PR is below (but we should clearly implement the C++ function instead of using the hack):

library(arrow, warn.conflicts = FALSE)

struct_array <- function(...) {
  batch <- record_batch(...)
  array_ptr <- arrow:::allocate_arrow_array()
  schema_ptr <- arrow:::allocate_arrow_schema()
  batch$export_to_c(array_ptr, schema_ptr)
  Array$import_from_c(array_ptr, schema_ptr)
}

struct_array(a = 1, b = "two")
#> StructArray
#> <struct<a: double, b: string>>
#> -- is_valid: all not null
#> -- child 0 type: double
#>   [
#>     1
#>   ]
#> -- child 1 type: string
#>   [
#>     "two"
#>   ]

Issue Links

• links to: GitHub Pull Request #14922