Struct Meta 

pub struct Meta {
    pub span: Span,
    pub expansion: Vec<(Arc<str>, Span)>,
    pub doc: Option<Arc<str>>,
    pub comments: Option<Box<Comments>>,
}

Everything a Node knows about itself beyond its shape.

Fields

span: Span

expansion: Vec<(Arc<str>, Span)>

The macro expansion chain this node came out of, innermost last. Empty for source code.

doc: Option<Arc<str>>

The ## doc comment written immediately above this node, lines joined by \n with the marker and one leading space stripped (crate::doc).

Metadata rather than a form, for the same reason a span is: a doc comment is not part of a node’s identity (Node::structurally_eq), so every pass that matches on def or model keeps working and a doc-only edit is not a change of meaning.

comments: Option<Box<Comments>>

The ordinary # comments written around this node (crate::doc).

Boxed and absent by default, because most nodes have none and every node pays for the field. Metadata for the same reason doc is: a comment is not part of a node’s identity, so adding one does not invalidate a memo or move an interface digest.

Implementations

impl Meta

pub fn at(span: Span) -> Meta

Trait Implementations

impl Clone for Meta

fn clone(&self) -> Meta

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Meta

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for Meta

fn default() -> Meta

Returns the “default value” for a type.