如何根据另一列的值重命名嵌套tibble中的列

Question

Sometimes I change column names of nested tibble depending on the value of another column.
I can do it preparing a function using in map() .

library(tidyverse)

# sample data
d <- tibble(col1 = 1:8, col2 = 11:18, group = letters[rep(1:2, each = 4)]) %>%
  nest(-group)

f <- function(data, group) rename(data, !!paste0(group, "_col1") := col1)

# Run
desired_output <- d %>%
  mutate(data = map2(data, group, f))

names(desired_output$data[[1]])  # "a_col1" "col2"   # work

I want to do it by anonymous function, but it doesn't work. Is there a way to do like mutate(map(rename(!!a := b))) with anonymous function? Thank you for any advice.

d %>%
  mutate(data2 = map2(data, group,
                      function(data, group) {
                        data %>%
                          rename(!!paste0(group, "_col1") := col1)
                      }))

# Error in paste0(group, "_col1") : object 'group' not found

Answer 1

I am not sure what you exactly mean by anonymous function but here is a way to do this without having to assign the function f to a variable:

d %>% 
  mutate(data = map2(data, group, ~rename_at(.x, 1, function(z) paste(.y, z, sep = "_"))))