Struct syn::buffer::Cursor

pub struct Cursor<'a> { /* fields omitted */ }

A cheaply copyable cursor into a TokenBuffer.

This cursor holds a shared reference into the immutable data which is used internally to represent a TokenStream, and can be efficiently manipulated and copied around.

An empty Cursor can be created directly, or one may create a TokenBuffer object and get a cursor to its first token with begin().

Two cursors are equal if they have the same location in the same input stream, and have the same scope.

See the module documentation for an example of a Cursor in action.

This type is available if Syn is built with the "parsing" feature.

Methods

impl<'a> Cursor<'a>

pub fn empty() -> Self

Creates a cursor referencing a static empty TokenStream.

pub fn eof(self) -> bool

Checks whether the cursor is currently pointing at the end of its valid scope.

pub fn group(self, delim: Delimiter) -> Option<(Cursor<'a>, Span, Cursor<'a>)>

If the cursor is pointing at a Group with the given delimiter, returns a cursor into that group and one pointing to the next TokenTree.

pub fn ident(self) -> Option<(Ident, Cursor<'a>)>

If the cursor is pointing at a Ident, returns it along with a cursor pointing at the next TokenTree.

pub fn punct(self) -> Option<(Punct, Cursor<'a>)>

If the cursor is pointing at an Punct, returns it along with a cursor pointing at the next TokenTree.

pub fn literal(self) -> Option<(Literal, Cursor<'a>)>

If the cursor is pointing at a Literal, return it along with a cursor pointing at the next TokenTree.

pub fn token_stream(self) -> TokenStream

Copies all remaining tokens visible from this cursor into a TokenStream.

pub fn token_tree(self) -> Option<(TokenTree, Cursor<'a>)>

If the cursor is pointing at a TokenTree, returns it along with a cursor pointing at the next TokenTree.

Returns None if the cursor has reached the end of its stream.

This method does not treat None-delimited groups as transparent, and will return a Group(None, ..) if the cursor is looking at one.

pub fn span(self) -> Span

Returns the Span of the current token, or Span::call_site() if this cursor points to eof.

Trait Implementations

impl<'a> Copy for Cursor<'a>

impl<'a> Clone for Cursor<'a>

fn clone(&self) -> Cursor<'a>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<'a> Eq for Cursor<'a>

impl<'a> PartialEq for Cursor<'a>

fn eq(&self, other: &Cursor<'a>) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Cursor<'a>) -> bool

This method tests for !=.