quos and nse, hard case

grouper_func_to_list.R

group_in_func <- function(x, ...) {
  x %>% 
    group_by(!!!(...)) %>% 
    summarise(sum(mpg))
}

list(quos(any_name=cyl == 6)) %>% 
  map(
    group_in_func, 
    x=head(select(as_tibble(mtcars), 1:2), 5) %>% print())
    
# A tibble: 5 x 2
    mpg   cyl
  <dbl> <dbl>
1  21       6
2  21       6
3  22.8     4
4  21.4     6
5  18.7     8
[[1]]
# A tibble: 2 x 2
  any_name `sum(mpg)`
  <lgl>         <dbl>
1 FALSE          41.5
2 TRUE           63.4