// The callers (Last/LastOrDefault) are blocking methods.
static TSource InternalLastOrDefault <TSource> (this IObservable <TSource> source, Func <TSource, bool> predicate, bool throwError)
{
if (source == null)
{
throw new ArgumentNullException("source");
}
if (predicate == null)
{
throw new ArgumentNullException("predicate");
}
var wait = new HybridWait();
TSource ret = default(TSource);
bool got = false;
var dis = source.Subscribe(
// the first "if (!got) check is required because the source may send next values before unsubscribing this action by dis.Dispose().
(s) => { if (predicate(s))
{
got = true; ret = s;
}
},
() => { wait.Set(); }
);
wait.WaitOne();
dis.Dispose();
if (!got && throwError)
{
throw new InvalidOperationException();
}
return(ret);
}
// The callers (Single/SingleOrDefault) are blocking methods.
static TSource InternalSingleOrDefault <TSource> (this IObservable <TSource> source, Func <TSource, bool> predicate, bool throwError)
{
if (source == null)
{
throw new ArgumentNullException("source");
}
if (predicate == null)
{
throw new ArgumentNullException("predicate");
}
var wait = new HybridWait();
TSource ret = default(TSource);
bool got = false, error = false;
IDisposable dis = null;
dis = source.Subscribe(
// the first "if (!got) check is required because the source may send next values before unsubscribing this action by dis.Dispose().
s => { if (predicate(s))
{
if (got)
{
error = true;
}
got = true;
ret = s;
}
},
() => wait.Set()
);
wait.WaitOne();
dis.Dispose();
if (error)
{
throw new InvalidOperationException("Observed that there was more than one item in the target object");
}
if (!got && throwError)
{
throw new InvalidOperationException();
}
return(ret);
}