pub fn highlight(code: &str) -> String {
    unsafe {
        let mut html_len: u64 = 0;
        let html_ptr = highlight_swift(code.as_ptr(), code.len() as u64, &mut html_len);
        String::from_raw_parts(html_ptr, html_len as usize, html_len as usize)
    }
}

extern "C" {
    fn highlight_swift(code_ptr: *const u8, code_len: u64, html_len_ptr: *mut u64) -> *mut u8;
}

#[cfg(test)]
mod tests {
    #[test]
    fn test_highlight() {
        let result = super::highlight("1+1");
        assert_eq!(
            result,
            r#"<span class="hl-num">1</span>+<span class="hl-num">1</span>"#
        );
    }
}