"." operator doesn't work in "mutate(map.." in some cases

tidyverse
,
1 
library(tidyverse)
tibble(a=1:3) %>% mutate(b = map(a, ~{length(.)}))
#> # A tibble: 3 x 2
#>       a b        
#>   <int> <list>   
#> 1     1 <int [1]>
#> 2     2 <int [1]>
#> 3     3 <int [1]>

tibble(a=1:3) %>% mutate(b = map(a, ~{n_distinct(.)}))
# Error in mutate_impl(.data, dots) : variable '.' not found

What is the problem?

2

Try updating your dplyr to the latest GH version, should be fixed!

library(tidyverse)
tibble(a=1:3) %>% mutate(b = map(a, ~{length(.)}))
#> # A tibble: 3 x 2
#>       a b        
#>   <int> <list>   
#> 1     1 <int [1]>
#> 2     2 <int [1]>
#> 3     3 <int [1]>

tibble(a=1:3) %>% mutate(b = map(a, ~{n_distinct(.)}))
#> # A tibble: 3 x 2
#>       a b        
#>   <int> <list>   
#> 1     1 <int [1]>
#> 2     2 <int [1]>
#> 3     3 <int [1]>

Created on 2018-09-27 by the reprex package (v0.2.1.9000)