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?

score 5 · Accepted Answer · answered Jun 23 '14 at 10:26

Three possibilities.

Use the ANY type.
```
m2 = setRefClass("m2",
  fields = list(x="ANY")
)
```
which, as the name, suggests allows you to have any type.

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)

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")

Multiple acceptable classes in reference class field list

1 Answers1