public static ICell <TResult> Derived <T1, T2, T3, T4, TResult>(ICell <T1> c1, ICell <T2> c2, ICell <T3> c3, ICell <T4> c4, Func <T1, T2, T3, T4, TResult> function)
{
if (c1 == null)
{
throw new ArgumentNullException(nameof(c1));
}
if (c2 == null)
{
throw new ArgumentNullException(nameof(c2));
}
if (c3 == null)
{
throw new ArgumentNullException(nameof(c3));
}
if (c4 == null)
{
throw new ArgumentNullException(nameof(c4));
}
var derived = new ManualCell <TResult>(() => function(c1.Value, c2.Value, c3.Value, c4.Value));
RegisterObserver(derived, c1);
RegisterObserver(derived, c2);
RegisterObserver(derived, c3);
RegisterObserver(derived, c4);
return(derived);
}
internal static ICell <TResult> Derived <T, TResult>(ICell <T> cell, Func <T, TResult> function)
{
var derived = new ManualCell <TResult>(() => function(cell.Value));
RegisterObserver(derived, cell);
return(derived);
}
public static ICell <TResult> Derived <T, TResult>(IEnumerable <ICell <T> > cells, Func <IEnumerable <T>, TResult> function)
{
if (cells == null)
{
throw new ArgumentNullException(nameof(cells));
}
var derived = new ManualCell <TResult>(() => function(cells.Select(cell => cell.Value)));
foreach (var cell in cells)
{
RegisterObserver(derived, cell);
}
return(derived);
}
private static void RegisterObserver <T, R>(ManualCell <R> derived, ICell <T> cell)
{
cell.ValueChanged += derived.Refresh;
}