rename / rework l_n_obs

[njtierney]

It is a very handy function, and I find that the other ways of getting the same piece of information are somewhat cumbersome:

library(brolgar)
library(tsibble)

l_n_obs(wages_ts)
#> # A tibble: 888 x 2
#>       id n_obs
#>    <int> <int>
#>  1    31     8
#>  2    36    10
#>  3    53     8
#>  4   122    10
#>  5   134    12
#>  6   145     9
#>  7   155    11
#>  8   173     6
#>  9   206     3
#> 10   207    11
#> # … with 878 more rows

wages_ts %>% features(id, length)
#> # A tibble: 888 x 2
#>       id    V1
#>    <int> <int>
#>  1    31     8
#>  2    36    10
#>  3    53     8
#>  4   122    10
#>  5   134    12
#>  6   145     9
#>  7   155    11
#>  8   173     6
#>  9   206     3
#> 10   207    11
#> # … with 878 more rows

wages_ts %>% features(!!index(wages_ts), length)
#> # A tibble: 888 x 2
#>       id    V1
#>    <int> <int>
#>  1    31     8
#>  2    36    10
#>  3    53     8
#>  4   122    10
#>  5   134    12
#>  6   145     9
#>  7   155    11
#>  8   173     6
#>  9   206     3
#> 10   207    11
#> # … with 878 more rows

wages_ts %>% features(!!index(wages_ts), 
                      list(n_obs = length))
#> # A tibble: 888 x 2
#>       id n_obs
#>    <int> <int>
#>  1    31     8
#>  2    36    10
#>  3    53     8
#>  4   122    10
#>  5   134    12
#>  6   145     9
#>  7   155    11
#>  8   173     6
#>  9   206     3
#> 10   207    11
#> # … with 878 more rows

^{Created on 2019-07-11 by the reprex package (v0.2.1)}

So then, what can I call it?

[njtierney]

How about n_key_obs()?