Multiple acceptable classes in reference class field list

Question

For example:

Mycls = setRefClass(
    "Mycls",
    fields = list(
    # this is just a mock up
    colorvec = "numeric" | "factor" | "matrix"
    )
)

In this example, I want to allow colorvec to be numeric or factor or matrix. Is there a way to do this?

Answer 1

Three possibilities.

1. Use the ANY type.

   m2 = setRefClass("m2",
     fields = list(x="ANY")
   )
   

   which, as the name, suggests allows you to have any type.

2. Create another class that only accepts numerics/factors/matrices:

   setClass("mult", representation(x="ANY"))
   setValidity("mult",
           function(object) 
                is.numeric(object@x) || is.factor(object@x) || is.matrix(object@x)
            )
   
   m3 = setRefClass("m3", fields = list(x="mult"))
   

   So

   bit = new("mult", x=10)
   m3$new(x=bit)
   

3. Have a function as your input and check the types. Notice that the x field doesn't actually store any data, it just checks and returns the internal value. You could create a simple show method to hide the internal field.

   m4 = setRefClass("m4",  
                fields=list(x = function(y){
                  if(!missing(y) && !is.null(y)) {
                    if(!(is.numeric(y))){
                      stop("Wrong type")
                    }  
                    internal <<- y
                  } else internal}
                  , 
                internal="ANY"
                ))
   
   m4$new(x=10)
   m4$new(x="10")