def highlight_regex(
        self,
        re_highlight: Union[Pattern[str], str],
        style: Optional[Union[GetStyleCallable, StyleType]] = None,
        *,
        style_prefix: str = "",
    ) -> int:
        """Highlight text with a regular expression, where group names are
        translated to styles.

        Args:
            re_highlight (Union[re.Pattern, str]): A regular expression object or string.
            style (Union[GetStyleCallable, StyleType]): Optional style to apply to whole match, or a callable
                which accepts the matched text and returns a style. Defaults to None.
            style_prefix (str, optional): Optional prefix to add to style group names.

        Returns:
            int: Number of regex matches
        """
        count = 0
        append_span = self._spans.append
        _Span = Span
        plain = self.plain
        if isinstance(re_highlight, str):
            re_highlight = re.compile(re_highlight)
        for match in re_highlight.finditer(plain):
            get_span = match.span
            if style:
                start, end = get_span()
                match_style = style(plain[start:end]) if callable(style) else style
                if match_style is not None and end > start:
                    append_span(_Span(start, end, match_style))

            count += 1
            for name in match.groupdict().keys():
                start, end = get_span(name)
                if start != -1 and end > start:
                    append_span(_Span(start, end, f"{style_prefix}{name}"))
        return count
Highlight text with a regular expression, where group names are
        translated to styles.

        Args:
            re_highlight (Union[re.Pattern, str]): A regular expression object or string.
            style (Union[GetStyleCallable, StyleType]): Optional style to apply to whole match, or a callable
                which accepts the matched text and returns a style. Defaults to None.
            style_prefix (str, optional): Optional prefix to add to style group names.

        Returns:
            int: Number of regex matches
        
rich/text.py