pub trait Whatsit: Debug {
// Provided method
fn hyphenation_hook(&self) { ... }
}Expand description
A whatsit node
This is used to facilitate extensions to TeX. It’s unclear right now how what the API of it will be, though it can be figured out by reading the Chapter 53 Extensions of TeX.
Knuth uses this node type to implement both \write and \special
so we’ll eventually find out.
Described in TeX.2021.146.