Function to perform case_when() to produce multiple colums

multi_case_when()

food <- tibble(item=c("apple","baguette","zucchini","mushrooms"))

multi_case_when <- function(.x,.names,...) {
  require(rlang)
  require(magrittr)
  require(purrr)
  
  .dots <- enquos(...)
  
  len_res <- .dots %>%
    map_int(. %>%
          quo_get_expr %>%
          extract2(3) %>%
          extract(-1) %>%
          length)
  
  if(any(len_res != length(.names))) {
    abort("Lengths in multi_case_when() must be all equal")
  }
  
  eval_env <- list2env(.x,parent=caller_env())
  
  .dots <- map(.dots,~quo_set_env(.,eval_env))
  .y <- .x
  
  for(i in 1:length(.names)){
    .exprs <- structure(map(.dots,
                            function(dot_element) {
                              dot_element %>%
                                quo_get_expr %>%
                                inset2(3,extract2(.,c(3,i+1))) %>%
                                quo_set_expr(dot_element,.)
                            }),
                        class=c("quosures","list"))
    .y$.res <- case_when(!!!.exprs)
    names(.y)[names(.y) == ".res"] <- .names[i]
  }
  .y
} 

food %>%
  multi_case_when(
    c("type","price"),
    item == "apple" ~ c("fruit",1),
    item == "baguette" ~ c("bread",2),
    item == "zucchini" ~ c("vegetable",0.5)
  )
  
#   A tibble: 4 x 3
#   item      type      price
#   <chr>     <chr>     <dbl>
# 1 apple     fruit       1  
# 2 baguette  bread       2  
# 3 zucchini  vegetable   0.5
# 4 mushrooms NA         NA