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>

fn empty() -> Self

Creates a cursor referencing a static empty TokenStream.

fn eof(self) -> bool

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

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.

fn term(self) -> Option<(Span, Term, Cursor<'a>)>

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

fn op(self) -> Option<(Span, char, Spacing, Cursor<'a>)>

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

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

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

fn token_stream(self) -> TokenStream

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

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.

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, __arg_0: &Cursor<'a>) -> bool

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

fn ne(&self, __arg_0: &Cursor<'a>) -> bool

This method tests for !=.