jonkeane commented on a change in pull request #10888:
URL: https://github.com/apache/arrow/pull/10888#discussion_r698579535
##########
File path: r/R/dataset-scan.R
##########
@@ -85,9 +86,30 @@ Scanner$create <- function(dataset,
# To handle mutate() on Table/RecordBatch, we need to
collect(as_data_frame=FALSE) now
dataset <- dplyr::collect(dataset, as_data_frame = FALSE)
}
+
+ proj <- c(dataset$selected_columns, dataset$temp_columns)
+
+ if (!is.null(projection)) {
+ if (is.character(projection)) {
+ proj <- proj[projection]
+ } else if (is_list_of(projection, "Expression")) {
+ # TODO: need to check and see if there are any Expressions that are
simply
+ # field refs in projections, but are richer expressions in proj?
+ proj <- projection
Review comment:
@nealrichardson do you have any thoughts on this? I've looked into using
`projection[[i]]$field_name` to identify any references to fields, and then
replace them with what's in `proj[projection[[i]]$field_name]`, which should
work for this case, but looks brittle to me (but maybe I'm being paranoid?).
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: [email protected]
For queries about this service, please contact Infrastructure at:
[email protected]
