Struct proc_macro2::Group

pub struct Group { /* private fields */ }

A delimited token stream.

A Group internally contains a TokenStream which is surrounded by Delimiters.

Implementations

impl Group

pub fn new(delimiter: Delimiter, stream: TokenStream) -> Self

Creates a new Group with the given delimiter and token stream.

This constructor will set the span for this group to Span::call_site(). To change the span you can use the set_span method below.

pub fn delimiter(&self) -> Delimiter

Returns the delimiter of this Group

pub fn stream(&self) -> TokenStream

Returns the TokenStream of tokens that are delimited in this Group.

Note that the returned token stream does not include the delimiter returned above.

pub fn span(&self) -> Span

Returns the span for the delimiters of this token stream, spanning the entire Group.

pub fn span(&self) -> Span {
           ^^^^^^^

Examples found in repository

src/lib.rs (line 581)

    pub fn span(&self) -> Span {
        match self {
            TokenTree::Group(t) => t.span(),
            TokenTree::Ident(t) => t.span(),
            TokenTree::Punct(t) => t.span(),
            TokenTree::Literal(t) => t.span(),
        }
    }

pub fn span_open(&self) -> Span

Returns the span pointing to the opening delimiter of this group.

pub fn span_open(&self) -> Span {
                ^

pub fn span_close(&self) -> Span

Returns the span pointing to the closing delimiter of this group.

pub fn span_close(&self) -> Span {
                       ^

pub fn set_span(&mut self, span: Span)

Configures the span for this Group’s delimiters, but not its internal tokens.

This method will not set the span of all the internal tokens spanned by this group, but rather it will only set the span of the delimiter tokens at the level of the Group.

Examples found in repository

src/lib.rs (line 595)

    pub fn set_span(&mut self, span: Span) {
        match self {
            TokenTree::Group(t) => t.set_span(span),
            TokenTree::Ident(t) => t.set_span(span),
            TokenTree::Punct(t) => t.set_span(span),
            TokenTree::Literal(t) => t.set_span(span),
        }
    }

src/parse.rs (line 831)

fn doc_comment<'a>(input: Cursor<'a>, trees: &mut TokenStreamBuilder) -> PResult<'a, ()> {
    #[cfg(span_locations)]
    let lo = input.off;
    let (rest, (comment, inner)) = doc_comment_contents(input)?;
    let span = crate::Span::_new_stable(Span {
        #[cfg(span_locations)]
        lo,
        #[cfg(span_locations)]
        hi: rest.off,
    });

    let mut scan_for_bare_cr = comment;
    while let Some(cr) = scan_for_bare_cr.find('\r') {
        let rest = &scan_for_bare_cr[cr + 1..];
        if !rest.starts_with('\n') {
            return Err(Reject);
        }
        scan_for_bare_cr = rest;
    }

    let mut pound = Punct::new('#', Spacing::Alone);
    pound.set_span(span);
    trees.push_token_from_parser(TokenTree::Punct(pound));

    if inner {
        let mut bang = Punct::new('!', Spacing::Alone);
        bang.set_span(span);
        trees.push_token_from_parser(TokenTree::Punct(bang));
    }

    let doc_ident = crate::Ident::new("doc", span);
    let mut equal = Punct::new('=', Spacing::Alone);
    equal.set_span(span);
    let mut literal = crate::Literal::string(comment);
    literal.set_span(span);
    let mut bracketed = TokenStreamBuilder::with_capacity(3);
    bracketed.push_token_from_parser(TokenTree::Ident(doc_ident));
    bracketed.push_token_from_parser(TokenTree::Punct(equal));
    bracketed.push_token_from_parser(TokenTree::Literal(literal));
    let group = Group::new(Delimiter::Bracket, bracketed.build());
    let mut group = crate::Group::_new_stable(group);
    group.set_span(span);
    trees.push_token_from_parser(TokenTree::Group(group));

    Ok((rest, ()))
}

Trait Implementations

impl Clone for Group

fn clone(&self) -> Group

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Group

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

Formats the value using the given formatter.

impl Display for Group

Prints the group as a string that should be losslessly convertible back into the same group (modulo spans), except for possibly TokenTree::Groups with Delimiter::None delimiters.

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

Formats the value using the given formatter.

impl From<Group> for TokenTree

fn from(g: Group) -> TokenTree

Converts to this type from the input type.