Struct Cursor

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

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.

Implementations

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 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.

pub 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.

pub 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.

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> 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> PartialEq for Cursor<'a>

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

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

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

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

impl<'a> StructuralPartialEq for Cursor<'a>