Select multiple data columns in function-CodePudding

How can I select for multiple existing columns from a dataframe when I index my function with the triple dots as a parameter?

for example:

devTest <- function(data,...){
  col = list(...)
  innerTest <- function(...){
    more = list(...)
    data %>% select(more)
  }
  x <- innerTest({{col}})
  x
}
devTest(mtcars,mpg, gear)

produces this error:

Error in devTest(mtcars, vs) : object 'vs' not found

CodePudding user response：

The main issue is that you need to defuse the arguments using enquos (since you want to pass column symbols rather than strings to devText):

devTest <- function(data, ...) {
    col <- enquos(...)
    innerTest <- function(col) {
        data %>% select(!!!col)
    }
    innerTest(col)
}
devTest(mtcars,mpg, gear)

Other minor issues are the duplicate list(...) calls which are not necessary, as we can define innerTest to take a list of quosures directly (which we can then evaluate using the triple-bang operator !!!).