arg-match.md

library(rlang)

preserved_goods_none <- function(goods = c("cucumber", "lemon", "pear")) {
  goods
}

preserved_goods_rlang <- function(goods = c("cucumber", "lemon", "pear")) {
  goods <- rlang::arg_match(
    arg = goods
  )

  goods
}

# this one is really fast but you need to specify `values` again
preserved_goods_rlang0 <- function(goods = c("cucumber", "lemon", "pear")) {
  goods <- rlang::arg_match0(
    arg = goods,
    values = c("cucumber", "lemon", "pear")
  )

  goods
}

preserved_goods_base <- function(goods = c("cucumber", "lemon", "pear")) {
  goods <- match.arg(
    arg = goods
  )

  goods
}

# no error catching; also prints all default values
preserved_goods_none()
#> [1] "cucumber" "lemon"    "pear"
preserved_goods_none(goods = "pear")
#> [1] "pear"
preserved_goods_none(goods = "apple")
#> [1] "apple"

# error catching, no partial matches, pretty printing
preserved_goods_rlang()
#> [1] "cucumber"
preserved_goods_rlang(goods = "pear")
#> [1] "pear"
preserved_goods_rlang(goods = "apple")
#> Error in `preserved_goods_rlang()`:
#> ! `goods` must be one of "cucumber", "lemon", or "pear", not "apple".
preserved_goods_rlang(goods = "pea")
#> Error in `preserved_goods_rlang()`:
#> ! `goods` must be one of "cucumber", "lemon", or "pear", not "pea".
#> ℹ Did you mean "pear"?

# error catching, partial matches, less-pretty printing
preserved_goods_base()
#> [1] "cucumber"
preserved_goods_base(goods = "pear")
#> [1] "pear"
preserved_goods_base(goods = "apple")
#> Error in match.arg(arg = goods): 'arg' should be one of "cucumber", "lemon", "pear"
preserved_goods_base(goods = "pea")
#> [1] "pear"

^{Created on 2025-03-17 with reprex v2.1.1}

Session info

sessioninfo::session_info()
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#>  date     2025-03-17
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