Enum LayerRef 

pub(crate) enum LayerRef<'layer> {
    Anonymous {
        start: usize,
        contexts: &'layer [StringContext],
    },
    Named(&'layer Layer),
}

A small wrapper around Layer, which allows us to conveniently handle anonymous layers.

Anonymous layers are ParseStack::pending context that hasn’t been added to a layer yet. This means that the outermost parser layer has not been closed.

Since we still want to show this context to users, we need some form of uniform representation for it.

Variants

Anonymous

Fields

start: usize

contexts: &'layer [StringContext]

Named(&'layer Layer)

Implementations

impl<'a> LayerRef<'a>

pub(crate) fn start(self) -> usize

The byte offset where this layer begins.

pub(crate) fn name(self) -> Option<&'a str>

The layer’s name.

None in case of an anonymous layer.

pub(crate) fn label_message(self) -> Option<String>

Returns the optional StringContext::Label messages, joined with commas.

Returns None if there are no StringContext::Label items.

pub(crate) fn descriptions(self) -> Option<String>

All StringContext::Description items joined in a String, without delimiter.

Returns None, if no descriptions exist or if they are all empty.

pub(crate) fn expected_literals(self) -> Vec<String>

Returns a list of all StringContext variants with literal values.

pub(crate) fn label(self) -> Option<&'a str>

Returns the very first StringContext::Label on this layer.

fn contexts(self) -> &'a [StringContext]

Returns a list of all StringContext values.

Trait Implementations

impl<'layer> Clone for LayerRef<'layer>

fn clone(&self) -> LayerRef<'layer>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<'layer> Copy for LayerRef<'layer>

impl<'layer> Debug for LayerRef<'layer>

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

Formats the value using the given formatter.