Different functions as function arguments in R-CodePudding

I would like to use different functions as function arguments in R where the arguments of the function arguments might be different. I have seen this post which describes the case where one can use different function arguments with the same argument for each function. Here is an example of what I would like:

f <- function(func, x, y) {
  return(func(x, y))
}

func1 <- function(x) {
  return(x^2)
}

func2 <- function(x, y) {
  return(x*y)
}

f(func1, 2) # not working: Error in func(x, y) : unused argument (y)
f(func1, 2, 3) # not working Error in func(x, y) : unused argument (y)
f(func2, 2, 3) # works

What I would like to be able to do is include a range of arguments (i.e. x, y etc. above) for f but, when writing the function to use as function argument (e.g. func1 and func2), not have to include all arguments in that function. i.e. I want to be able to write func1(x) but not have include y as an argument. Setting default parameters does not help and I seem to not be able to use ... in the right way either.

CodePudding user response：

Since you have differing arguments, I believe if you replace the inputs with ... may help:

f <- function(func, ...) {
  func <- match.fun(func) # Rui Barradas's comment to avoid matching with other objects
  return(func(...))
}
func1 <- function(x, ...) {
  return(x^2)
}

func2 <- function(x, y) {
  return(x*y)
}

f(func1, 2) 
f(func1, 2, 3) 
f(func2, x = 2, y = 3)

Output:

# > f(func1, 2) 
# [1]  4
# > f(func1, 2, 3) 
# [1] 4
# > f(func2, x = 2, y = 3)
# [1] 6