It would be handy to pass the fun parameter of fct_relabel to rlang::as_function so it can accept formula (~tolower(.x)) or quosure (quo(tolower(.x)) style functions or string function names ("tolower") instead of just raw functions.
A trivial reprex (though realistically regex is the obvious use-case):
library(tidyverse)
library(forcats)
# Right now this is the only option for an anonymous function:
iris %>%
tbl_df() %>%
mutate(Species = fct_relabel(Species,
function(x){substr(x, 1, 3)}))
#> # A tibble: 150 x 5
#> Sepal.Length Sepal.Width Petal.Length Petal.Width Species
#> <dbl> <dbl> <dbl> <dbl> <fctr>
#> 1 5.1 3.5 1.4 0.2 set
#> 2 4.9 3.0 1.4 0.2 set
#> 3 4.7 3.2 1.3 0.2 set
#> 4 4.6 3.1 1.5 0.2 set
#> 5 5.0 3.6 1.4 0.2 set
#> 6 5.4 3.9 1.7 0.4 set
#> 7 4.6 3.4 1.4 0.3 set
#> 8 5.0 3.4 1.5 0.2 set
#> 9 4.4 2.9 1.4 0.2 set
#> 10 4.9 3.1 1.5 0.1 set
#> # ... with 140 more rows
# ...but this syntax would be convenient and consistent with the rest of the tidyverse:
iris %>%
tbl_df() %>%
mutate(Species = fct_relabel(Species,
~substr(.x, 1, 3)))
#> Error in mutate_impl(.data, dots): Evaluation error: Expected function, got formula.
# ...and it would work:
iris %>%
tbl_df() %>%
mutate(Species = fct_relabel(Species,
rlang::as_function(~substr(.x, 1, 3))))
#> # A tibble: 150 x 5
#> Sepal.Length Sepal.Width Petal.Length Petal.Width Species
#> <dbl> <dbl> <dbl> <dbl> <fctr>
#> 1 5.1 3.5 1.4 0.2 set
#> 2 4.9 3.0 1.4 0.2 set
#> 3 4.7 3.2 1.3 0.2 set
#> 4 4.6 3.1 1.5 0.2 set
#> 5 5.0 3.6 1.4 0.2 set
#> 6 5.4 3.9 1.7 0.4 set
#> 7 4.6 3.4 1.4 0.3 set
#> 8 5.0 3.4 1.5 0.2 set
#> 9 4.4 2.9 1.4 0.2 set
#> 10 4.9 3.1 1.5 0.1 set
#> # ... with 140 more rowsThe tradeoff for the convenience is that it requires adding rlang as a dependency. If that's ok, I'd be happy to assemble a PR if you like.
It would be handy to pass the
funparameter offct_relabeltorlang::as_functionso it can accept formula (~tolower(.x)) or quosure (quo(tolower(.x)) style functions or string function names ("tolower") instead of just raw functions.A trivial reprex (though realistically regex is the obvious use-case):
The tradeoff for the convenience is that it requires adding rlang as a dependency. If that's ok, I'd be happy to assemble a PR if you like.