/// <summary>
/// Returns the label with the given name.
///
/// Throws KeyNotFoundException if no label by that name is found".
/// </summary>
public Label this[string name]
{
get
{
if (!InnerLookup.ContainsKey(name))
{
throw new KeyNotFoundException("No label with name '" + name + "' found");
}
return(InnerLookup[name]);
}
}
public IEnumerator <IGrouping <keyˈ, valueˈ> > GetEnumerator() => InnerLookup.Where(g => Filter(g.Key)).GetEnumerator();
public bool Contains(keyˈ key) => Filter(key) && InnerLookup.Contains(key);
public IEnumerable <valueˈ> this[keyˈ key] => Filter(key) ? InnerLookup.Get(key) : Enumerable.Empty <valueˈ>();
public IEnumerator <IGrouping <keyˈ, valueˈ> > GetEnumerator() => InnerLookup.Select(g => g.Map(g.Key, (k, v) => Projection(k, v))).GetEnumerator();
public bool Contains(keyˈ key) => InnerLookup.Contains(key);
