[ARROW-16577] [R] dplyr `n` function cannot be called with `dplyr::n()`

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Duplicate
• Affects Version/s: 8.0.0
• Component/s: R
• External issue URL: https://github.com/apache/arrow/issues/20246

Language

R

• Assignee: Unassigned
• Reporter: Sam Bashevkin
• Created: 13/May/22 23:50
• Updated: 11/Jan/23 11:45
• Resolved: 14/May/22 15:46

Description

I am trying to summarize an arrow dataset in R using the `n` function from dplyr, but I noticed that it does not work when called via the `dplyr::n` syntax, even though it works fine just as `n`. I also tried the `n_distinct` function with the same issue

``` r
library(arrow)
#> 
#> Attaching package: 'arrow'
#> The following object is masked from 'package:utils':
#> 
#>     timestamp
library(dplyr)
#> 
#> Attaching package: 'dplyr'
#> The following objects are masked from 'package:stats':
#> 
#>     filter, lag
#> The following objects are masked from 'package:base':
#> 
#>     intersect, setdiff, setequal, union
dir<-file.path(tempdir(), "test-data")
test_data <- data.frame(A=1:10)
write_dataset(test_data, dir)

1. This does work
   data2<-open_dataset(dir)%>%
       summarise(N=n())
   data2
   #> FileSystemDataset (query)
   #> N: int32
   #> 
   #> See $.data for the source Arrow object
   collect(data2)
   #> # A tibble: 1 × 1
   #>       N
   #>   <int>
   #> 1    10

1. But this does not work
   data1<-open_dataset(dir)%>%
       summarise(N=dplyr::n())
   #> Error: Error : Expression dplyr::n() not supported in Arrow
   #> Call collect() first to pull data into R.
   data1
   #> Error in eval(expr, envir, enclos): object 'data1' not found
   ```

^{Created on 2022-05-13 by the [reprex package](https://reprex.tidyverse.org) (v2.0.1)}

<details style="margin-bottom:10px;">
<summary>
Session info
</summary>

``` r
sessioninfo::session_info()
#> ─ Session info ───────────────────────────────────────────────────────────────
#>  setting  value
#>  version  R version 4.2.0 (2022-04-22 ucrt)
#>  os       Windows 10 x64 (build 19044)
#>  system   x86_64, mingw32
#>  ui       RTerm
#>  language (EN)
#>  collate  English_United States.utf8
#>  ctype    English_United States.utf8
#>  tz       America/Los_Angeles
#>  date     2022-05-13
#>  pandoc   2.17.1.1 @ C:/Program Files/RStudio/bin/quarto/bin/ (via rmarkdown)
#> 
#> ─ Packages ───────────────────────────────────────────────────────────────────
#>  package     * version date (UTC) lib source
#>  arrow       * 8.0.0   2022-05-09 [1] CRAN (R 4.2.0)
#>  assertthat    0.2.1   2019-03-21 [1] CRAN (R 4.2.0)
#>  bit           4.0.4   2020-08-04 [1] CRAN (R 4.2.0)
#>  bit64         4.0.5   2020-08-30 [1] CRAN (R 4.2.0)
#>  cli           3.3.0   2022-04-25 [1] CRAN (R 4.2.0)
#>  crayon        1.5.1   2022-03-26 [1] CRAN (R 4.2.0)
#>  DBI           1.1.2   2021-12-20 [1] CRAN (R 4.2.0)
#>  digest        0.6.29  2021-12-01 [1] CRAN (R 4.2.0)
#>  dplyr       * 1.0.9   2022-04-28 [1] CRAN (R 4.2.0)
#>  ellipsis      0.3.2   2021-04-29 [1] CRAN (R 4.2.0)
#>  evaluate      0.15    2022-02-18 [1] CRAN (R 4.2.0)
#>  fansi         1.0.3   2022-03-24 [1] CRAN (R 4.2.0)
#>  fastmap       1.1.0   2021-01-25 [1] CRAN (R 4.2.0)
#>  fs            1.5.2   2021-12-08 [1] CRAN (R 4.2.0)
#>  generics      0.1.2   2022-01-31 [1] CRAN (R 4.2.0)
#>  glue          1.6.2   2022-02-24 [1] CRAN (R 4.2.0)
#>  highr         0.9     2021-04-16 [1] CRAN (R 4.2.0)
#>  htmltools     0.5.2   2021-08-25 [1] CRAN (R 4.2.0)
#>  knitr         1.39    2022-04-26 [1] CRAN (R 4.2.0)
#>  lifecycle     1.0.1   2021-09-24 [1] CRAN (R 4.2.0)
#>  magrittr      2.0.3   2022-03-30 [1] CRAN (R 4.2.0)
#>  pillar        1.7.0   2022-02-01 [1] CRAN (R 4.2.0)
#>  pkgconfig     2.0.3   2019-09-22 [1] CRAN (R 4.2.0)
#>  purrr         0.3.4   2020-04-17 [1] CRAN (R 4.2.0)
#>  R6            2.5.1   2021-08-19 [1] CRAN (R 4.2.0)
#>  reprex        2.0.1   2021-08-05 [1] CRAN (R 4.2.0)
#>  rlang         1.0.2   2022-03-04 [1] CRAN (R 4.2.0)
#>  rmarkdown     2.14    2022-04-25 [1] CRAN (R 4.2.0)
#>  rstudioapi    0.13    2020-11-12 [1] CRAN (R 4.2.0)
#>  sessioninfo   1.2.2   2021-12-06 [1] CRAN (R 4.2.0)
#>  stringi       1.7.6   2021-11-29 [1] CRAN (R 4.2.0)
#>  stringr       1.4.0   2019-02-10 [1] CRAN (R 4.2.0)
#>  tibble        3.1.7   2022-05-03 [1] CRAN (R 4.2.0)
#>  tidyselect    1.1.2   2022-02-21 [1] CRAN (R 4.2.0)
#>  tzdb          0.3.0   2022-03-28 [1] CRAN (R 4.2.0)
#>  utf8          1.2.2   2021-07-24 [1] CRAN (R 4.2.0)
#>  vctrs         0.4.1   2022-04-13 [1] CRAN (R 4.2.0)
#>  withr         2.5.0   2022-03-03 [1] CRAN (R 4.2.0)
#>  xfun          0.31    2022-05-10 [1] CRAN (R 4.2.0)
#>  yaml          2.3.5   2022-02-21 [1] CRAN (R 4.2.0)
#> 
#>  [1] C:/Users/sbashevkin/AppData/Local/R/win-library/4.2
#>  [2] C:/Program Files/R/R-4.2.0/library
#> 
#> ──────────────────────────────────────────────────────────────────────────────
```

</details>

Issue Links

• duplicates: ARROW-14575 [R] Allow functions with {{pkg::}} prefixes