swc-project/swc · error

Expected '-' between start and end in unicode range

Error message

Expected '-' between start and end in unicode range

What it means

Fired during <urange> parsing: after the start value, if text remains it must begin with '-' (U+002D) separating start and end values. Any other character where the hyphen is expected invalidates the production.

Source

Thrown at crates/swc_css_parser/src/parser/values_and_units/mod.rs:2997

        // Otherwise, interpret the consumed code points as a hexadecimal number. This
        // is the start value.

        // 4. If there are no code points left in text, The end value is the same as the
        // start value. Exit this algorithm.
        if next.is_none() {
            return Ok(UnicodeRange {
                span: span!(self, span.lo),
                start: self.input.atom(start),
                end: None,
                raw: Some(self.input.atom(unicode_range)),
            });
        }

        // 5. If the next code point in text is U+002D HYPHEN-MINUS (-), consume it.
        // Otherwise, this is an invalid <urange>, and this algorithm must exit.
        if next != Some('-') {
            return Err(Error::new(
                span,
                ErrorKind::Expected("'-' between start and end in unicode range"),
            ));
        } else {
            next = chars.next();
        }

        // 6. Consume as many hex digits as possible from text.
        // If zero hex digits were consumed, or more than 6 hex digits were consumed,
        // this is an invalid <urange>, and this algorithm must exit. If there are any
        // code points left in text, this is an invalid <urange>, and this algorithm
        // must exit.
        let mut end = String::new();

        loop {
            match next {
                Some(c) if c.is_ascii_digit() => {
                    end.push(c);

View on GitHub (pinned to 5176682b65)

Solutions

1. Separate start and end with '-': 'U+0-7F'
2. Remove extra characters if a single code point was intended

When it happens

Trigger: Thrown at crates/swc_css_parser/src/parser/values_and_units/mod.rs:2997 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of swc-project/swc@5176682b65 (2026-08-17). Data as JSON: /api/errors/3ce43214f41ae796. Report an issue: GitHub.