Method parse_expectation_range

src/attribute.rs:251–362

(
        &self,
        mut cursor: Cursor<'a>,
    )

    }

    fn parse_expectation_range<'a>(
        &self,
        mut cursor: Cursor<'a>,
    ) -> Result<((u32, Option<u32>), Cursor<'a>), ErrorGuaranteed> {
        let expect_range = |span| {
            Err(self.tcx.dcx().emit_err(InvalidPreemptCountAttribute {
                span,
                help: "a range expected",
            }))
        };

        let start_span = cursor.peek().span();
        let mut start = 0;
        if !matches!(
            cursor.peek(),
            TokenTree::Token(
                token::Token {
                    kind: token::TokenKind::DotDot | token::TokenKind::DotDotEq,
                    ..
                },
                _
            )
        ) {
            let token = cursor.next();
            let TokenTree::Token(
                token::Token {
                    kind: token::TokenKind::Literal(lit),
                    ..
                },
                _,
            ) = token
            else {
                expect_range(token.span())?
            };
            if lit.kind != token::LitKind::Integer {
                expect_range(token.span())?;
            }
            let Some(v) = lit.symbol.as_str().parse::<u32>().ok() else {
                expect_range(token.span())?;
            };
            start = v;
        }

        let inclusive = match cursor.peek() {
            TokenTree::Token(
                token::Token {
                    kind: token::TokenKind::DotDot,
                    ..
                },
                _,
            ) => Some(false),
            TokenTree::Token(
                token::Token {
                    kind: token::TokenKind::DotDotEq,
                    ..
                },
                _,
            ) => Some(true),