Coerce arguments to simplest type

Question

When dealing with user input using packages shiny or plumber one often needs to convert character arguments to numeric or logical.

I would like to do it automatically, what's an efficient way to do it ?

expected (this or similar) :

convert_args <- ...

fun <- function(a, b, c, d){
  convert_args()
  dplyr::lst(a, b, c , d)
}

fun("na","true","1","foo")
#> $a
#> [1] NA
#> 
#> $b
#> [1] TRUE
#> 
#> $c
#> [1] 1
#> 
#> $d
#> [1] "foo"

Answer 1

One option is to use readr::parse_guess which as the name suggests tries to guess the type of the character vector.

convert_args <- function(x) {
  lapply(x, readr::parse_guess)  
}

convert_args(c("NA","true","1","foo"))
#[[1]]
#[1] NA

#[[2]]
#[1] TRUE

#[[3]]
#[1] 1

#[[4]]
#[1] "foo"

This doesn't directly work when we have "na"

readr::parse_guess("na")
#[1] "na"

but as @Moody_Mudskipper mentions it can be resolved specifying na argument in parse_guess

readr::parse_guess("na", c("na", "NA"))
#[1] NA