internal static Lookup <TKey, TElement> Create(IEnumerable <TElement> source, Func <TElement, TKey> keySelector, IEqualityComparer <TKey> comparer) { Debug.Assert(source != null); Debug.Assert(keySelector != null); var lookup = new Lookup <TKey, TElement>(comparer); foreach (var item in source) { lookup.GetGrouping(keySelector(item), create: true) .Add(item); } return(lookup); }
internal static async Task <Lookup <TKey, TElement> > CreateForJoinAsync(IAsyncEnumerable <TElement> source, Func <TElement, TKey> keySelector, IEqualityComparer <TKey> comparer, CancellationToken cancellationToken) { var lookup = new Lookup <TKey, TElement>(comparer); await foreach (var item in source.WithCancellation(cancellationToken).ConfigureAwait(false)) { var key = keySelector(item); if (key != null) { lookup.GetGrouping(key, create: true).Add(item); } } return(lookup); }
internal static async Task <Lookup <TKey, TElement> > CreateAsync(IAsyncEnumerable <TElement> source, Func <TElement, TKey> keySelector, IEqualityComparer <TKey> comparer, CancellationToken cancellationToken) { Debug.Assert(source != null); Debug.Assert(keySelector != null); var lookup = new Lookup <TKey, TElement>(comparer); await foreach (var item in AsyncEnumerableExtensions.WithCancellation(source, cancellationToken).ConfigureAwait(false)) { var key = keySelector(item); lookup.GetGrouping(key, create: true).Add(item); } return(lookup); }
internal static Lookup <TKey, TElement> CreateForJoin(IEnumerable <TElement> source, Func <TElement, TKey> keySelector, IEqualityComparer <TKey> comparer) { var lookup = new Lookup <TKey, TElement>(comparer); foreach (var item in source) { var key = keySelector(item); if (key != null) { lookup.GetGrouping(key, create: true) .Add(item); } } return(lookup); }
internal static async Task <Lookup <TKey, TElement> > CreateAsync(IAsyncEnumerable <TElement> source, Func <TElement, TKey> keySelector, IEqualityComparer <TKey> comparer, CancellationToken cancellationToken) { Debug.Assert(source != null); Debug.Assert(keySelector != null); var lookup = new Lookup <TKey, TElement>(comparer); using (var enu = source.GetEnumerator()) { while (await enu.MoveNext(cancellationToken) .ConfigureAwait(false)) { lookup.GetGrouping(keySelector(enu.Current), create: true) .Add(enu.Current); } } return(lookup); }
protected override async Task <bool> MoveNextCore(CancellationToken cancellationToken) { switch (state) { case AsyncIteratorState.Allocated: outerEnumerator = outer.GetEnumerator(); mode = State_Begin; state = AsyncIteratorState.Iterating; goto case AsyncIteratorState.Iterating; case AsyncIteratorState.Iterating: switch (mode) { case State_Begin: if (await outerEnumerator.MoveNext(cancellationToken) .ConfigureAwait(false)) { lookup = await Internal.Lookup <TKey, TInner> .CreateForJoinAsync(inner, innerKeySelector, comparer, cancellationToken).ConfigureAwait(false); if (lookup.Count != 0) { mode = State_DoLoop; goto case State_DoLoop; } } break; case State_DoLoop: item = outerEnumerator.Current; var g = lookup.GetGrouping(outerKeySelector(item), create: false); if (g != null) { count = g._count; elements = g._elements; index = 0; mode = State_For; goto case State_For; } break; case State_For: current = resultSelector(item, elements[index]); index++; if (index == count) { mode = State_While; } return(true); case State_While: var hasNext = await outerEnumerator.MoveNext(cancellationToken).ConfigureAwait(false); if (hasNext) { goto case State_DoLoop; } break; } Dispose(); break; } return(false); }
protected override async ValueTask <bool> MoveNextCore() { switch (_state) { case AsyncIteratorState.Allocated: _outerEnumerator = _outer.GetAsyncEnumerator(_cancellationToken); _mode = State_If; _state = AsyncIteratorState.Iterating; goto case AsyncIteratorState.Iterating; case AsyncIteratorState.Iterating: switch (_mode) { case State_If: if (await _outerEnumerator.MoveNextAsync().ConfigureAwait(false)) { _lookup = await Internal.Lookup <TKey, TInner> .CreateForJoinAsync(_inner, _innerKeySelector, _comparer, _cancellationToken).ConfigureAwait(false); if (_lookup.Count != 0) { _mode = State_DoLoop; goto case State_DoLoop; } } break; case State_DoLoop: _item = _outerEnumerator.Current; var g = _lookup.GetGrouping(_outerKeySelector(_item), create: false); if (g != null) { _count = g._count; _elements = g._elements; _index = 0; _mode = State_For; goto case State_For; } // advance to while _mode = State_While; goto case State_While; case State_For: _current = _resultSelector(_item, _elements[_index]); _index++; if (_index == _count) { _mode = State_While; } return(true); case State_While: var hasNext = await _outerEnumerator.MoveNextAsync().ConfigureAwait(false); if (hasNext) { goto case State_DoLoop; } break; } await DisposeAsync().ConfigureAwait(false); break; } return(false); }