class Parser::LexerStrings

def unicode_points(p)
  @escape = ""
  codepoints = tok(@escape_s + 2, p - 1)
  codepoint_s = @escape_s + 2
  if @version < 24
    if codepoints.start_with?(" ") || codepoints.start_with?("\t")
      diagnostic :fatal, :invalid_unicode_escape, nil,
                 range(@escape_s + 2, @escape_s + 3)
    end
    if spaces_p = codepoints.index(/[ \t]{2}/)
      diagnostic :fatal, :invalid_unicode_escape, nil,
                 range(codepoint_s + spaces_p + 1, codepoint_s + spaces_p + 2)
    end
    if codepoints.end_with?(" ") || codepoints.end_with?("\t")
      diagnostic :fatal, :invalid_unicode_escape, nil, range(p - 1, p)
    end
  end
  codepoints.scan(/([0-9a-fA-F]+)|([ \t]+)/).each do |(codepoint_str, spaces)|
    if spaces
      codepoint_s += spaces.length
    else
      codepoint = codepoint_str.to_i(16)
      if codepoint >= 0x110000
        diagnostic :error, :unicode_point_too_large, nil,
                   range(codepoint_s, codepoint_s + codepoint_str.length)
        break
      end
      @escape += codepoint.chr(Encoding::UTF_8)
      codepoint_s += codepoint_str.length
    end
  end
end