/// <summary>
/// Merges differently typed sequences into a <see cref="ValueTuple{T1, T2, T3}"/>.
/// </summary>
/// <remarks>
/// <paramref name="startAtFirstElement"/> determines how the start of the sequence is handled.
/// If it's false (the default), the operator only produces elements once all sources have produced their first element.
/// If it's true, the sequence starts at the first element produced by any source,
/// with default values for any source that has not yet produced a value.
/// </remarks>
public static IAsyncEnumerable <ValueTuple <T1, T2, T3> > Combine <T1, T2, T3>(this
IAsyncEnumerable <T1> source1,
IAsyncEnumerable <T2> source2,
IAsyncEnumerable <T3> source3,
bool startAtFirstElement = false)
{
if (source1 == null)
{
throw new ArgumentNullException(nameof(source1));
}
if (source2 == null)
{
throw new ArgumentNullException(nameof(source2));
}
if (source3 == null)
{
throw new ArgumentNullException(nameof(source3));
}
return(Defer(() =>
{
var tuple = new CombineTuple <T1, T2, T3>(startAtFirstElement);
return new[]
{
source1.Select(v => tuple.OnNext1(v)),
source2.Select(v => tuple.OnNext2(v)),
source3.Select(v => tuple.OnNext3(v)),
}
.Merge()
.SkipUntil(t => t.HasValue)
.Select(t => t.GetValueOrDefault());
}));
}
/// <summary>
/// Merges differently typed sequences into a <see cref="ValueTuple{T1, T2, T3, T4, T5, T6, T7}"/>.
/// </summary>
/// <remarks>
/// <paramref name="startAtFirstElement"/> determines how the start of the sequence is handled.
/// If it's false (the default), the operator only produces elements once all sources have produced their first element.
/// If it's true, the sequence starts at the first element produced by any source,
/// with default values for any source that has not yet produced a value.
/// </remarks>
public static IAsyncEnumerable <ValueTuple <T1, T2, T3, T4, T5, T6, T7> > Combine <T1, T2, T3, T4, T5, T6, T7>(this
IAsyncEnumerable <T1> source1,
IAsyncEnumerable <T2> source2,
IAsyncEnumerable <T3> source3,
IAsyncEnumerable <T4> source4,
IAsyncEnumerable <T5> source5,
IAsyncEnumerable <T6> source6,
IAsyncEnumerable <T7> source7,
bool startAtFirstElement = false)
{
if (source1 == null)
{
throw new ArgumentNullException(nameof(source1));
}
if (source2 == null)
{
throw new ArgumentNullException(nameof(source2));
}
if (source3 == null)
{
throw new ArgumentNullException(nameof(source3));
}
if (source4 == null)
{
throw new ArgumentNullException(nameof(source4));
}
if (source5 == null)
{
throw new ArgumentNullException(nameof(source5));
}
if (source6 == null)
{
throw new ArgumentNullException(nameof(source6));
}
if (source7 == null)
{
throw new ArgumentNullException(nameof(source7));
}
return(Defer(() =>
{
var tuple = new CombineTuple <T1, T2, T3, T4, T5, T6, T7>(startAtFirstElement);
return new[]
{
source1.Select(v => tuple.OnNext1(v)),
source2.Select(v => tuple.OnNext2(v)),
source3.Select(v => tuple.OnNext3(v)),
source4.Select(v => tuple.OnNext4(v)),
source5.Select(v => tuple.OnNext5(v)),
source6.Select(v => tuple.OnNext6(v)),
source7.Select(v => tuple.OnNext7(v)),
}
.Merge()
.SkipUntil(t => t.HasValue)
.Select(t => t.GetValueOrDefault());
}));
}