/// <summary>
/// Adds a <see cref="Value"/> instance to the extent set manange by
/// this instance. If the new value has the same code as an existing
/// entry it will replace it and a reference to the old instance will
/// be returned to the caller.
/// </summary>
/// <param name="value">The scheme <see cref="Value"/> to be added.</param>
/// <returns>The old <see cref="Value"/> instance having the same code
/// as the new one, otherwise <c>null</c>.</returns>
protected internal Value Add(Value value)
{
Value result = values.ContainsKey (value.Code) ? values [value.Code] : null;
values [value.Code] = value;
return (result);
}
/// <summary>
/// Finds the subset of scheme values that match the provided regular
/// expression. No particular ordering of the values is enforced.
/// </summary>
/// <param name="pattern">A regular expression.</param>
/// <returns>An array containing the matching <see cref="Value"/> instances.</returns>
public Value[] Like(string pattern)
{
ArrayList matches = new ArrayList ();
Regex regex = new Regex (pattern);
Value [] result;
foreach (Value value in values.Values)
if (regex.IsMatch (value.Code)) matches.Add (value);
result = new Value [matches.Count];
matches.CopyTo (result, 0);
return (result);
}