/// <summary>
/// Applies an accumulator function over a sequence. The specified seed value is used as the
/// initial accumulator value.
/// </summary>
/// <typeparam name="TSource">The type of the elements of <paramref name="source"/>.</typeparam>
/// <typeparam name="TAccumulate">The type of the accumulator value.</typeparam>
/// <param name="source">An <see cref="IBindableCollection{TElement}"/> to aggregate over.</param>
/// <param name="seed">The initial accumulator value.</param>
/// <param name="func">An accumulator function to be invoked on each element.</param>
/// <param name="dependencyAnalysisMode">The dependency analysis mode.</param>
/// <returns>The final accumulator value.</returns>
public static IBindable <TAccumulate> Aggregate <TSource, TAccumulate>(this IBindableCollection <TSource> source, TAccumulate seed, Expression <Func <TAccumulate, TSource, TAccumulate> > func, DependencyDiscovery dependencyAnalysisMode)
{
source.ShouldNotBeNull("source");
func.ShouldNotBeNull("func");
seed.ShouldNotBeNull("seed");
var compiledAccumulator = func.Compile();
var function = new Func <IBindableCollection <TSource>, TAccumulate>(
sourceElements =>
{
var current = seed;
foreach (var sourceElement in sourceElements)
{
current = compiledAccumulator(current, sourceElement);
}
return(current);
}
);
var result = new CustomAggregator <TSource, TAccumulate>(source, function, source.Dispatcher);
if (dependencyAnalysisMode == DependencyDiscovery.Enabled)
{
return(result.DependsOnExpression(func, func.Parameters[1]));
}
return(result);
}
/// <summary>
/// Applies an accumulator function over a sequence.
/// </summary>
/// <typeparam name="TSource">The type of the elements of <paramref name="source"/>.</typeparam>
/// <typeparam name="TResult">The type of the result.</typeparam>
/// <param name="source">An <see cref="IBindableCollection{TSource}"/> to aggregate over.</param>
/// <param name="func">An accumulator function to be invoked on each element.</param>
/// <param name="dependencyAnalysisMode">The dependency analysis mode.</param>
/// <returns>The final accumulator value.</returns>
public static IBindable <TResult> Aggregate <TSource, TResult>(this IBindableCollection <TSource> source, Expression <Func <IBindableCollection <TSource>, TResult> > func, DependencyDiscovery dependencyAnalysisMode)
{
source.ShouldNotBeNull("source");
func.ShouldNotBeNull("func");
var result = new CustomAggregator <TSource, TResult>(source, func.Compile(), source.Dispatcher);
if (dependencyAnalysisMode == DependencyDiscovery.Enabled)
{
return(result.DependsOnExpression(func, func.Parameters[0]));
}
return(result);
}
