Enum VisitTarget 

pub enum VisitTarget<'a, 'doc> {
    Node(&'a Node<'doc>),
    Attribute(&'a Attribute<'doc>),
}

What the canonicalize_with visibility predicate is being asked about.

Mirrors the targets libxml2’s xmlC14NIsVisibleCallback is invoked against: element/text/comment/PI nodes, and individual attributes. Namespace declarations are emitted per the C14N algorithm rules and are not surfaced through this predicate.

Variants

Node(&'a Node<'doc>)

An element, text, CDATA, comment, PI, or entity-reference node. Returning false for an element causes the entire subtree to be skipped (XML-DSig “subtree exclusion” semantics); returning false for a non-element node skips just that node.

Attribute(&'a Attribute<'doc>)

An individual attribute on an element. Returning false causes that attribute to be omitted from the element’s canonical serialization.