minor legend simplification

[vincentarelbundock]

This is totally optional. Feel free to close if you don't think the code is clearer.

Mostly replaced is.null() checks with a fill_null() helper, and inserted some isTRUE to simplify checks.

[grantmcdermott]

Cool idea.

I wonder, though, whether we should make this a general function and move to utils.R?

At least, I've been thinking along those lines since R.4.4.0 introduced the L %||% R null coalescing operator:

The null coalescing operator %||% is a simple 1-line function: x %||% y is an idiomatic way to call

if (is.null(x)) y else x
                         # or equivalently, of course,
if(!is.null(x)) x else y 

Maybe we could do something as simple as:

if (getRversion() <= "4.4.0" ) {
   `%||%` = function (x, y) if (is.null(x)) y else x
}

?

[vincentarelbundock]

yep, seems to work. I just pushed this.

[grantmcdermott]

Great, thanks. Let's wait for #284 and then merge this