I’m generating multiple columns in a mutate() call, all by using a function of 1) an already-existing column and 2) some value which is different for each output column. The following code produces what I want, but it smells:

df <- tibble(base_string = c("a", "b", "c"))
df_desired_result <- df |>
  mutate(
    one = str_c(base_string, "1"),
    two = str_c(base_string, "2"),
    three = str_c(base_string, "3")
  )

If there were many other columns, this would be a bad solution.

The best improvement I’ve come up with is:

df_also_desired_result <- df |>
  expand_grid(
    tibble(
      number_name = c("one", "two", "three"),
      number_string = c("1", "2", "3")
    )
  ) |>
  mutate(final_string = str_c(base_string, number_string)) |>
  pivot_wider(
    id_cols = base_string,
    names_from = number_name,
    values_from = final_string
  )

But this seems too verbose. Would love any suggestions on a nicer way to do this.