Support tidyselect

[vRadAdamBender]

With dtplyr not all tidyselect verbs are supported. Can this be implemented?

Error in across():
! This tidyselect interface doesn't support predicates.
Backtrace:

[markfairbanks]

where() doesn't work with dtplyr (or dbplyr) since they work lazily. This means columns don't necessarily exist until collect() is called. Unfortunately there's no way to add this functionality, either, hence the error message ! This tidyselect interface doesn't support predicates.

It's also worth noting that other tidyselect functions work just fine - starts_with(), ends_with(), etc.

library(dtplyr)
library(dplyr, warn.conflicts = FALSE)

iris %>%
  lazy_dt() %>%
  select(starts_with("S"))
#> Source: local data table [150 x 3]
#> Call:   `_DT1`[, .(Sepal.Length, Sepal.Width, Species)]
#> 
#>   Sepal.Length Sepal.Width Species
#>          <dbl>       <dbl> <fct>  
#> 1          5.1         3.5 setosa 
#> 2          4.9         3   setosa 
#> 3          4.7         3.2 setosa 
#> 4          4.6         3.1 setosa 
#> 5          5           3.6 setosa 
#> 6          5.4         3.9 setosa 
#> # ℹ 144 more rows
#> 
#> # Use as.data.table()/as.data.frame()/as_tibble() to access results

Hope this helps! If you have any questions let me know.