Struct Checkpoint 

pub struct Checkpoint<P>(/* private fields */)
where
    P: Copy;

The identifier of a node as returned by functions such as Builder::checkpoint.

This can be used as a checkpoint in Builder::close_at, and a checkpoint can be fetched up front from Builder::checkpoint.

Checkpoints and cloned builders

A checkpoint belongs to the builder that handed it out, and closing it updates it in place. A cloned Builder hands out its own checkpoints, so one taken from the clone can be used on it without affecting the original. A checkpoint taken before cloning still belongs to the original: closing it on the clone updates it for the original too, so get a fresh checkpoint from the clone instead.

let mut a = syntree::Builder::new();
let c = a.checkpoint()?;

let mut b = a.clone();
let c2 = b.checkpoint()?;
b.token("lit", 1)?;
b.close_at(&c2, "speculative")?;

a.token("lit", 1)?;
a.close_at(&c, "root")?;

assert_eq!(a.build()?, syntree::tree! { "root" => { ("lit", 1) } });

Trait Implementations

impl<P> Clone for Checkpoint<P>

where P: Copy + Clone,

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<P> Debug for Checkpoint<P>

where P: Copy + Debug,

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

Formats the value using the given formatter.