Node Name Cannot be NA

[billdenney]

Thank you for the package!

I have just started using data.tree, and I was wanting to make a multi-rooted tree. With a quick look, it doesn't seem like multiple roots are supported (that is a reasonable design decision), so I decided to make an NA-like node. Specifically, I made a node with

data.tree::Node$new(NA_character_)

to be the fake root, and I put all the intended roots under that so that they could represent the multiple trees.

When I used FindNode() on it, an error occurred due to a missing value. That makes sense that NA names would not be supported, but I think it would help to either modify the code to support NA names or to make it an error to create an NA name.

As an aside, I also tried to make a fake root with data.tree::Node$new(NULL), and that gave an error as well.

library(data.tree)
root <- data.tree::Node$new(NA_character_)
FindNode(root, "foo")
#> Error in if (length(filterFun) == 0 || filterFun(node)) {: missing value where TRUE/FALSE needed

^{Created on 2021-01-08 by the reprex package (v0.3.0)}

If interested, I'd be happy to try to make a PR to do one of the following:

• Ensure that the name is a non-NA character scalar.
• Allow the name to be NA_character_ (while ensuring that it is a character scalar).

[gluc]

Hey Bill, thx for this! I think both would work for me, but I slightly prefer the first solution, i.e. "Ensure that the name is a non-NA char scalar" (one can always use an empty string "" as a workaround for a dummy node).
Yes, I would be more than thankful for a PR!