public static AsyncMaybe <TResult> ZipAsync <T1, T2, TResult>(
this AsyncMaybe <T1> first,
AsyncMaybe <T2> second,
[InstantHandle, NotNull] Func <T1, T2, Task <TResult> > zipper
)
{
if (zipper == null)
{
throw new ArgumentNullException(nameof(zipper));
}
return(first.FlatMap(
some1 => second.MapAsync(
some2 => zipper(some1, some2)
)
));
}
public static AsyncMaybe <TResult> ZipAsync <T1, T2, T3, T4, TResult>(
this AsyncMaybe <T1> first,
AsyncMaybe <T2> second,
AsyncMaybe <T3> third,
AsyncMaybe <T4> fourth,
[InstantHandle, NotNull] Func <T1, T2, T3, T4, Task <TResult> > zipper
)
{
if (zipper == null)
{
throw new ArgumentNullException(nameof(zipper));
}
return(first.FlatMap <T1, TResult>(
some1 => second.FlatMap <T2, TResult>(
some2 => third.FlatMap <T3, TResult>(
some3 => fourth.MapAsync <T4, TResult>(
some4 => zipper(some1, some2, some3, some4)
)
)
)
));
}
public static AsyncMaybe <TResult> SelectAsync <T, TResult>(
this AsyncMaybe <T> source,
[NotNull] Func <T, Task <TResult> > mapper
) => source.MapAsync(mapper);
