class Gem::URI::RFC2396_Parser

def split(uri)
  case uri
  when ''
    # null uri
  when @regexp[:ABS_URI]
    scheme, opaque, userinfo, host, port,
      registry, path, query, fragment = $~[1..-1]
    # Gem::URI-reference = [ absoluteURI | relativeURI ] [ "#" fragment ]
    # absoluteURI   = scheme ":" ( hier_part | opaque_part )
    # hier_part     = ( net_path | abs_path ) [ "?" query ]
    # opaque_part   = uric_no_slash *uric
    # abs_path      = "/"  path_segments
    # net_path      = "//" authority [ abs_path ]
    # authority     = server | reg_name
    # server        = [ [ userinfo "@" ] hostport ]
    if !scheme
      raise InvalidURIError,
        "bad Gem::URI (absolute but no scheme): #{uri}"
    end
    if !opaque && (!path && (!host && !registry))
      raise InvalidURIError,
        "bad Gem::URI (absolute but no path): #{uri}"
    end
  when @regexp[:REL_URI]
    scheme = nil
    opaque = nil
    userinfo, host, port, registry,
      rel_segment, abs_path, query, fragment = $~[1..-1]
    if rel_segment && abs_path
      path = rel_segment + abs_path
    elsif rel_segment
      path = rel_segment
    elsif abs_path
      path = abs_path
    end
    # Gem::URI-reference = [ absoluteURI | relativeURI ] [ "#" fragment ]
    # relativeURI   = ( net_path | abs_path | rel_path ) [ "?" query ]
    # net_path      = "//" authority [ abs_path ]
    # abs_path      = "/"  path_segments
    # rel_path      = rel_segment [ abs_path ]
    # authority     = server | reg_name
    # server        = [ [ userinfo "@" ] hostport ]
  else
    raise InvalidURIError, "bad Gem::URI (is not Gem::URI?): #{uri}"
  end
  path = '' if !path && !opaque # (see RFC2396 Section 5.2)
  ret = [
    scheme,
    userinfo, host, port,         # X
    registry,                     # X
    path,                         # Y
    opaque,                       # Y
    query,
    fragment
  ]
  return ret
end