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• About

About

Bud.Reactive is a set of calming and option-gathering extension methods for the IObservable<T> type of .NET Reactive Extensions.

Calming

These are the currently available calming methods:

CalmedBatches

var resulting = original.CalmedBatches(TimeSpan.FromMilliseconds(5));

This method keeps collecting elements from the original observable until no new element arrives for a specific amount of time. At this instant it passes the array of collected elements to the resulting observable, and starts collecting elements again.

Note that the resulting observable will never contain empty arrays.

The following timelines illustrates the behaviour of this method:

Original observable:

   a   b     c          d  e
|--^---^--+--^------+---^--^--+---------|
^         ^         ^         ^         ^
0         10        20        30        40 ms

Resulting observable:

            [a,b] [c]           [d,e]
|---------+-^-----^-+---------+-^-------|
^         ^         ^         ^         ^
0         10        20        30        40 ms

Calmed

var resulting = original.Calmed(TimeSpan.FromMilliseconds(5));

This method is similar to CalmedBatches with the difference that this method only passes the last element to the resulting observable.

Original observable:

   a   b     c          d  e
|--^---^--+--^------+---^--^--+---------|
^         ^         ^         ^         ^
0         10        20        30        40 ms

Resulting observable:

            b     c             e
|---------+-^-----^-+---------+-^-------|
^         ^         ^         ^         ^
0         10        20        30        40 ms

FirstThenCalmed

var resulting = original.FirstThenCalmed(TimeSpan.FromMilliseconds(5));

This method is similar to Calmed with the difference that this method passes through the first element and then starts to behave exactly the same as Calmed.

Resulting observable:

   a   b     c          d  e
|--^---^--+--^------+---^--^--+---------|
^         ^         ^         ^         ^
0         10        20        30        40 ms

Original observable:

   a        b     c             e
|--^------+-^-----^-+---------+-^-------|
^         ^         ^         ^         ^
0         10        20        30        40 ms

Gathering

The observable gathering API provides an overloaded extension method that works with observables in conjunction with option types.

IObservable<T> Gather<T>(this IObservable<Option<T>> observable);

IObservable<TResult> Gather<TSource, TResult>(this IObservable<TSource> observable,
                                              Func<TSource, Option<TResult>> selector)

The first overload discards from the original observable all options without values. Options with values are not discarded. Their contained values are passed to the resulting observable.

The second overload first applies a selector function on each element of the original observable. The selector function returns an option. This option is discarded if it contains no value. Otherwise the element contained in it is passed on to the resulting observable.