/// <summary>
/// Read the string up to the <see cref="Rune"/> which is equal to <paramref name="r"/> or until EOF is reached.
/// </summary>
/// <param name="parser">A parser on which to operate.</param>
/// <param name="r"></param>
/// <returns>A parser string containing the read characters.</returns>
public static ParserString ReadUntil(this ITextParser parser, Rune r)
{
return(parser.ReadUntil(rune => rune == r));
}