Added support for passing Range as a parameter to .Exclude. (#619)

Co-authored-by: Taco <65432314+tradinglounge@users.noreply.github.com> Co-authored-by: Stuart Turner <stuart@turner-isageek.com>
viceroypenguin · Feb 22, 2024 · 635691e · 635691e
1 parent 886ca78
commit 635691e
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diff --git a/Source/SuperLinq/Exclude.cs b/Source/SuperLinq/Exclude.cs
@@ -1,4 +1,4 @@
-namespace SuperLinq;
+namespace SuperLinq;
 
 public static partial class SuperEnumerable
 {
@@ -35,43 +35,98 @@ public static IEnumerable<T> Exclude<T>(this IEnumerable<T> sequence, int startI
 		ArgumentOutOfRangeException.ThrowIfNegative(startIndex);
 		ArgumentOutOfRangeException.ThrowIfNegative(count);
 
-		if (count == 0)
-			return sequence;
-
-		return sequence switch
+		return (count, sequence) switch
 		{
-			IList<T> list => new ExcludeListIterator<T>(list, startIndex, count),
-			ICollection<T> collection => new ExcludeCollectionIterator<T>(collection, startIndex, count),
+			(0, _) => sequence,
+			(_, IList<T> list) => new ExcludeListIterator<T>(list, startIndex, count),
+			(_, ICollection<T> collection) => new ExcludeCollectionIterator<T>(collection, startIndex, count),
 			_ => ExcludeCore(sequence, startIndex, count)
 		};
 	}
 
-	private sealed class ExcludeCollectionIterator<T>(
-		ICollection<T> source,
-		int startIndex,
-		int count
-	) : CollectionIterator<T>
+	/// <summary>
+	///	    Excludes a contiguous number of elements from a sequence starting at a given index.
+	/// </summary>
+	/// <typeparam name="T">
+	///	    The type of the elements of the sequence
+	/// </typeparam>
+	/// <param name="sequence">
+	///	    The sequence to exclude elements from
+	/// </param>
+	/// <param name="range">
+	///	    The zero-based index at which to begin excluding elements
+	/// </param>
+	/// <returns>
+	///	    A sequence that excludes the specified portion of elements
+	/// </returns>
+	/// <exception cref="ArgumentNullException">
+	///	    <paramref name="sequence"/> is <see langword="null" />.
+	/// </exception>
+	/// <exception cref="ArgumentOutOfRangeException">
+	///	    <paramref name="range.Start.Value"/> or <paramref name="range.End.Value"/> is less than <c>0</c>.
+	/// </exception>
+	/// <remarks>
+	///	    This method uses deferred execution and streams its results.
+	/// </remarks>
+	public static IEnumerable<T> Exclude<T>(this IEnumerable<T> sequence, Range range)
+	{
+		ArgumentNullException.ThrowIfNull(sequence);
+
+		var startFromEnd = range.Start.IsFromEnd;
+		var endFromEnd = range.End.IsFromEnd;
+		if ((startFromEnd, endFromEnd) == (false, false))
+		{
+			return Exclude(sequence, range.Start.Value, range.End.Value - range.Start.Value);
+		}
+
+		if (sequence.TryGetCollectionCount() is int count)
+		{
+			var (start, length) = range.GetOffsetAndLength(count);
+			return Exclude(sequence, start, length);
+		}
+
+		return (startFromEnd, endFromEnd) switch
+		{
+			(false, true) => ExcludeEndFromEnd(sequence, range),
+			(true, false) => ExcludeStartFromEnd(sequence, range),
+			(true, true) when range.Start.Value < range.End.Value =>
+				ThrowHelper.ThrowArgumentOutOfRangeException<IEnumerable<T>>("length"),
+			_ => ExcludeRange(sequence, range),
+		};
+	}
+
+	/// <summary>
+	/// Represents an iterator for excluding elements from a collection.
+	/// </summary>
+	/// <typeparam name="T">Specifies the type of elements in the collection.</typeparam>
+	private sealed class ExcludeCollectionIterator<T>(ICollection<T> source, int startIndex, int count)
+		: CollectionIterator<T>
 	{
+		/// <summary>
+		/// Gets the number of elements in the source collection after excluding the specified portion of elements.
+		/// </summary>
 		public override int Count =>
 			source.Count < startIndex ? source.Count :
 			source.Count < startIndex + count ? startIndex :
 			source.Count - count;
 
+		/// <inheritdoc cref="IEnumerable{T}" /> 
 		protected override IEnumerable<T> GetEnumerable() =>
 			ExcludeCore(source, startIndex, count);
 	}
 
-	private sealed class ExcludeListIterator<T>(
-		IList<T> source,
-		int startIndex,
-		int count
-	) : ListIterator<T>
+	private sealed class ExcludeListIterator<T>(IList<T> source, int startIndex, int count)
+		: ListIterator<T>
 	{
+		/// <summary>
+		/// Gets the number of elements in the source collection after excluding the specified portion of elements.
+		/// </summary>
 		public override int Count =>
 			source.Count < startIndex ? source.Count :
 			source.Count < startIndex + count ? startIndex :
 			source.Count - count;
 
+		/// <inheritdoc cref="IEnumerable{T}" />
 		protected override IEnumerable<T> GetEnumerable()
 		{
 			var cnt = (uint)source.Count;
@@ -82,6 +137,7 @@ protected override IEnumerable<T> GetEnumerable()
 				yield return source[i];
 		}
 
+		/// <inheritdoc cref="IEnumerable{T}"/>
 		protected override T ElementAt(int index)
 		{
 			ArgumentOutOfRangeException.ThrowIfNegative(index);
@@ -102,7 +158,81 @@ private static IEnumerable<T> ExcludeCore<T>(IEnumerable<T> sequence, int startI
 		{
 			if (index < startIndex || index >= endIndex)
 				yield return item;
+
 			index++;
 		}
 	}
+
+	private static IEnumerable<T> ExcludeRange<T>(IEnumerable<T> sequence, Range range)
+	{
+		var start = range.Start.Value;
+		var queue = new Queue<T>(start + 1);
+		foreach (var e in sequence)
+		{
+			queue.Enqueue(e);
+			if (queue.Count > start)
+				yield return queue.Dequeue();
+		}
+
+		start = Math.Min(start, queue.Count);
+		var length = start - range.End.Value;
+		while (length > 0)
+		{
+			if (!queue.TryDequeue(out var _))
+				yield break;
+			length--;
+		}
+
+		while (queue.TryDequeue(out var element))
+			yield return element;
+	}
+
+	private static IEnumerable<T> ExcludeStartFromEnd<T>(IEnumerable<T> sequence, Range range)
+	{
+		var count = 0;
+		var start = range.Start.Value;
+		var queue = new Queue<T>(start + 1);
+		foreach (var e in sequence)
+		{
+			count++;
+			queue.Enqueue(e);
+			if (queue.Count > start)
+				yield return queue.Dequeue();
+		}
+
+		start = Math.Max(range.Start.GetOffset(count), 0);
+		var length = range.End.Value - start;
+
+		while (length > 0)
+		{
+			if (!queue.TryDequeue(out var _))
+				yield break;
+			length--;
+		}
+
+		while (queue.TryDequeue(out var element))
+			yield return element;
+	}
+
+	private static IEnumerable<T> ExcludeEndFromEnd<T>(IEnumerable<T> sequence, Range range)
+	{
+		var count = 0;
+		var start = range.Start.Value;
+		var end = range.End.Value;
+		var queue = new Queue<T>(end + 1);
+		foreach (var e in sequence)
+		{
+			count++;
+			queue.Enqueue(e);
+			if (queue.Count > end)
+			{
+				var el = queue.Dequeue();
+				if ((count - end) <= start)
+					yield return el;
+			}
+		}
+
+		while (queue.TryDequeue(out var element))
+			yield return element;
+	}
 }
diff --git a/Source/SuperLinq/PublicAPI/net6.0/PublicAPI.Unshipped.txt b/Source/SuperLinq/PublicAPI/net6.0/PublicAPI.Unshipped.txt
@@ -95,6 +95,7 @@ static SuperLinq.SuperEnumerable.DenseRank<TSource>(this System.Collections.Gene
 static SuperLinq.SuperEnumerable.DenseRank<TSource>(this System.Collections.Generic.IEnumerable<TSource>! source, System.Collections.Generic.IComparer<TSource>! comparer, SuperLinq.OrderByDirection sortDirection) -> System.Collections.Generic.IEnumerable<(TSource item, int rank)>!
 static SuperLinq.SuperEnumerable.DenseRankBy<TSource, TKey>(this System.Collections.Generic.IEnumerable<TSource>! source, System.Func<TSource, TKey>! keySelector, SuperLinq.OrderByDirection sortDirection) -> System.Collections.Generic.IEnumerable<(TSource item, int rank)>!
 static SuperLinq.SuperEnumerable.DenseRankBy<TSource, TKey>(this System.Collections.Generic.IEnumerable<TSource>! source, System.Func<TSource, TKey>! keySelector, System.Collections.Generic.IComparer<TKey>! comparer, SuperLinq.OrderByDirection sortDirection) -> System.Collections.Generic.IEnumerable<(TSource item, int rank)>!
+static SuperLinq.SuperEnumerable.Exclude<T>(this System.Collections.Generic.IEnumerable<T>! sequence, System.Range range) -> System.Collections.Generic.IEnumerable<T>!
 static SuperLinq.SuperEnumerable.FullOuterHashJoin<TLeft, TRight, TKey, TResult>(this System.Collections.Generic.IEnumerable<TLeft>! left, System.Collections.Generic.IEnumerable<TRight>! right, System.Func<TLeft, TKey>! leftKeySelector, System.Func<TRight, TKey>! rightKeySelector, System.Func<TLeft, TResult>! leftResultSelector, System.Func<TRight, TResult>! rightResultSelector, System.Func<TLeft, TRight, TResult>! bothResultSelector, System.Collections.Generic.IEqualityComparer<TKey>? comparer = null) -> System.Collections.Generic.IEnumerable<TResult>!
 static SuperLinq.SuperEnumerable.FullOuterHashJoin<TLeft, TRight, TKey>(this System.Collections.Generic.IEnumerable<TLeft>! left, System.Collections.Generic.IEnumerable<TRight>! right, System.Func<TLeft, TKey>! leftKeySelector, System.Func<TRight, TKey>! rightKeySelector, System.Collections.Generic.IEqualityComparer<TKey>? comparer = null) -> System.Collections.Generic.IEnumerable<(TLeft? Left, TRight? Right)>!
 static SuperLinq.SuperEnumerable.FullOuterMergeJoin<TLeft, TRight, TKey, TResult>(this System.Collections.Generic.IEnumerable<TLeft>! left, System.Collections.Generic.IEnumerable<TRight>! right, System.Func<TLeft, TKey>! leftKeySelector, System.Func<TRight, TKey>! rightKeySelector, System.Func<TLeft, TResult>! leftResultSelector, System.Func<TRight, TResult>! rightResultSelector, System.Func<TLeft, TRight, TResult>! bothResultSelector, System.Collections.Generic.IComparer<TKey>? comparer = null) -> System.Collections.Generic.IEnumerable<TResult>!

diff --git a/Source/SuperLinq/PublicAPI/net7.0/PublicAPI.Unshipped.txt b/Source/SuperLinq/PublicAPI/net7.0/PublicAPI.Unshipped.txt
@@ -95,6 +95,7 @@ static SuperLinq.SuperEnumerable.DenseRank<TSource>(this System.Collections.Gene
 static SuperLinq.SuperEnumerable.DenseRank<TSource>(this System.Collections.Generic.IEnumerable<TSource>! source, System.Collections.Generic.IComparer<TSource>! comparer, SuperLinq.OrderByDirection sortDirection) -> System.Collections.Generic.IEnumerable<(TSource item, int rank)>!
 static SuperLinq.SuperEnumerable.DenseRankBy<TSource, TKey>(this System.Collections.Generic.IEnumerable<TSource>! source, System.Func<TSource, TKey>! keySelector, SuperLinq.OrderByDirection sortDirection) -> System.Collections.Generic.IEnumerable<(TSource item, int rank)>!
 static SuperLinq.SuperEnumerable.DenseRankBy<TSource, TKey>(this System.Collections.Generic.IEnumerable<TSource>! source, System.Func<TSource, TKey>! keySelector, System.Collections.Generic.IComparer<TKey>! comparer, SuperLinq.OrderByDirection sortDirection) -> System.Collections.Generic.IEnumerable<(TSource item, int rank)>!
+static SuperLinq.SuperEnumerable.Exclude<T>(this System.Collections.Generic.IEnumerable<T>! sequence, System.Range range) -> System.Collections.Generic.IEnumerable<T>!
 static SuperLinq.SuperEnumerable.FullOuterHashJoin<TLeft, TRight, TKey, TResult>(this System.Collections.Generic.IEnumerable<TLeft>! left, System.Collections.Generic.IEnumerable<TRight>! right, System.Func<TLeft, TKey>! leftKeySelector, System.Func<TRight, TKey>! rightKeySelector, System.Func<TLeft, TResult>! leftResultSelector, System.Func<TRight, TResult>! rightResultSelector, System.Func<TLeft, TRight, TResult>! bothResultSelector, System.Collections.Generic.IEqualityComparer<TKey>? comparer = null) -> System.Collections.Generic.IEnumerable<TResult>!
 static SuperLinq.SuperEnumerable.FullOuterHashJoin<TLeft, TRight, TKey>(this System.Collections.Generic.IEnumerable<TLeft>! left, System.Collections.Generic.IEnumerable<TRight>! right, System.Func<TLeft, TKey>! leftKeySelector, System.Func<TRight, TKey>! rightKeySelector, System.Collections.Generic.IEqualityComparer<TKey>? comparer = null) -> System.Collections.Generic.IEnumerable<(TLeft? Left, TRight? Right)>!
 static SuperLinq.SuperEnumerable.FullOuterMergeJoin<TLeft, TRight, TKey, TResult>(this System.Collections.Generic.IEnumerable<TLeft>! left, System.Collections.Generic.IEnumerable<TRight>! right, System.Func<TLeft, TKey>! leftKeySelector, System.Func<TRight, TKey>! rightKeySelector, System.Func<TLeft, TResult>! leftResultSelector, System.Func<TRight, TResult>! rightResultSelector, System.Func<TLeft, TRight, TResult>! bothResultSelector, System.Collections.Generic.IComparer<TKey>? comparer = null) -> System.Collections.Generic.IEnumerable<TResult>!

diff --git a/Source/SuperLinq/PublicAPI/net8.0/PublicAPI.Unshipped.txt b/Source/SuperLinq/PublicAPI/net8.0/PublicAPI.Unshipped.txt
@@ -95,6 +95,7 @@ static SuperLinq.SuperEnumerable.DenseRank<TSource>(this System.Collections.Gene
 static SuperLinq.SuperEnumerable.DenseRank<TSource>(this System.Collections.Generic.IEnumerable<TSource>! source, System.Collections.Generic.IComparer<TSource>! comparer, SuperLinq.OrderByDirection sortDirection) -> System.Collections.Generic.IEnumerable<(TSource item, int rank)>!
 static SuperLinq.SuperEnumerable.DenseRankBy<TSource, TKey>(this System.Collections.Generic.IEnumerable<TSource>! source, System.Func<TSource, TKey>! keySelector, SuperLinq.OrderByDirection sortDirection) -> System.Collections.Generic.IEnumerable<(TSource item, int rank)>!
 static SuperLinq.SuperEnumerable.DenseRankBy<TSource, TKey>(this System.Collections.Generic.IEnumerable<TSource>! source, System.Func<TSource, TKey>! keySelector, System.Collections.Generic.IComparer<TKey>! comparer, SuperLinq.OrderByDirection sortDirection) -> System.Collections.Generic.IEnumerable<(TSource item, int rank)>!
+static SuperLinq.SuperEnumerable.Exclude<T>(this System.Collections.Generic.IEnumerable<T>! sequence, System.Range range) -> System.Collections.Generic.IEnumerable<T>!
 static SuperLinq.SuperEnumerable.FullOuterHashJoin<TLeft, TRight, TKey, TResult>(this System.Collections.Generic.IEnumerable<TLeft>! left, System.Collections.Generic.IEnumerable<TRight>! right, System.Func<TLeft, TKey>! leftKeySelector, System.Func<TRight, TKey>! rightKeySelector, System.Func<TLeft, TResult>! leftResultSelector, System.Func<TRight, TResult>! rightResultSelector, System.Func<TLeft, TRight, TResult>! bothResultSelector, System.Collections.Generic.IEqualityComparer<TKey>? comparer = null) -> System.Collections.Generic.IEnumerable<TResult>!
 static SuperLinq.SuperEnumerable.FullOuterHashJoin<TLeft, TRight, TKey>(this System.Collections.Generic.IEnumerable<TLeft>! left, System.Collections.Generic.IEnumerable<TRight>! right, System.Func<TLeft, TKey>! leftKeySelector, System.Func<TRight, TKey>! rightKeySelector, System.Collections.Generic.IEqualityComparer<TKey>? comparer = null) -> System.Collections.Generic.IEnumerable<(TLeft? Left, TRight? Right)>!
 static SuperLinq.SuperEnumerable.FullOuterMergeJoin<TLeft, TRight, TKey, TResult>(this System.Collections.Generic.IEnumerable<TLeft>! left, System.Collections.Generic.IEnumerable<TRight>! right, System.Func<TLeft, TKey>! leftKeySelector, System.Func<TRight, TKey>! rightKeySelector, System.Func<TLeft, TResult>! leftResultSelector, System.Func<TRight, TResult>! rightResultSelector, System.Func<TLeft, TRight, TResult>! bothResultSelector, System.Collections.Generic.IComparer<TKey>? comparer = null) -> System.Collections.Generic.IEnumerable<TResult>!

diff --git a/Source/SuperLinq/PublicAPI/net9.0/PublicAPI.Unshipped.txt b/Source/SuperLinq/PublicAPI/net9.0/PublicAPI.Unshipped.txt
@@ -95,6 +95,7 @@ static SuperLinq.SuperEnumerable.DenseRank<TSource>(this System.Collections.Gene
 static SuperLinq.SuperEnumerable.DenseRank<TSource>(this System.Collections.Generic.IEnumerable<TSource>! source, System.Collections.Generic.IComparer<TSource>! comparer, SuperLinq.OrderByDirection sortDirection) -> System.Collections.Generic.IEnumerable<(TSource item, int rank)>!
 static SuperLinq.SuperEnumerable.DenseRankBy<TSource, TKey>(this System.Collections.Generic.IEnumerable<TSource>! source, System.Func<TSource, TKey>! keySelector, SuperLinq.OrderByDirection sortDirection) -> System.Collections.Generic.IEnumerable<(TSource item, int rank)>!
 static SuperLinq.SuperEnumerable.DenseRankBy<TSource, TKey>(this System.Collections.Generic.IEnumerable<TSource>! source, System.Func<TSource, TKey>! keySelector, System.Collections.Generic.IComparer<TKey>! comparer, SuperLinq.OrderByDirection sortDirection) -> System.Collections.Generic.IEnumerable<(TSource item, int rank)>!
+static SuperLinq.SuperEnumerable.Exclude<T>(this System.Collections.Generic.IEnumerable<T>! sequence, System.Range range) -> System.Collections.Generic.IEnumerable<T>!
 static SuperLinq.SuperEnumerable.FullOuterHashJoin<TLeft, TRight, TKey, TResult>(this System.Collections.Generic.IEnumerable<TLeft>! left, System.Collections.Generic.IEnumerable<TRight>! right, System.Func<TLeft, TKey>! leftKeySelector, System.Func<TRight, TKey>! rightKeySelector, System.Func<TLeft, TResult>! leftResultSelector, System.Func<TRight, TResult>! rightResultSelector, System.Func<TLeft, TRight, TResult>! bothResultSelector, System.Collections.Generic.IEqualityComparer<TKey>? comparer = null) -> System.Collections.Generic.IEnumerable<TResult>!
 static SuperLinq.SuperEnumerable.FullOuterHashJoin<TLeft, TRight, TKey>(this System.Collections.Generic.IEnumerable<TLeft>! left, System.Collections.Generic.IEnumerable<TRight>! right, System.Func<TLeft, TKey>! leftKeySelector, System.Func<TRight, TKey>! rightKeySelector, System.Collections.Generic.IEqualityComparer<TKey>? comparer = null) -> System.Collections.Generic.IEnumerable<(TLeft? Left, TRight? Right)>!
 static SuperLinq.SuperEnumerable.FullOuterMergeJoin<TLeft, TRight, TKey, TResult>(this System.Collections.Generic.IEnumerable<TLeft>! left, System.Collections.Generic.IEnumerable<TRight>! right, System.Func<TLeft, TKey>! leftKeySelector, System.Func<TRight, TKey>! rightKeySelector, System.Func<TLeft, TResult>! leftResultSelector, System.Func<TRight, TResult>! rightResultSelector, System.Func<TLeft, TRight, TResult>! bothResultSelector, System.Collections.Generic.IComparer<TKey>? comparer = null) -> System.Collections.Generic.IEnumerable<TResult>!

diff --git a/Source/SuperLinq/PublicAPI/netcoreapp3.1/PublicAPI.Unshipped.txt b/Source/SuperLinq/PublicAPI/netcoreapp3.1/PublicAPI.Unshipped.txt
@@ -95,6 +95,7 @@ static SuperLinq.SuperEnumerable.DenseRank<TSource>(this System.Collections.Gene
 static SuperLinq.SuperEnumerable.DenseRank<TSource>(this System.Collections.Generic.IEnumerable<TSource>! source, System.Collections.Generic.IComparer<TSource>! comparer, SuperLinq.OrderByDirection sortDirection) -> System.Collections.Generic.IEnumerable<(TSource item, int rank)>!
 static SuperLinq.SuperEnumerable.DenseRankBy<TSource, TKey>(this System.Collections.Generic.IEnumerable<TSource>! source, System.Func<TSource, TKey>! keySelector, SuperLinq.OrderByDirection sortDirection) -> System.Collections.Generic.IEnumerable<(TSource item, int rank)>!
 static SuperLinq.SuperEnumerable.DenseRankBy<TSource, TKey>(this System.Collections.Generic.IEnumerable<TSource>! source, System.Func<TSource, TKey>! keySelector, System.Collections.Generic.IComparer<TKey>! comparer, SuperLinq.OrderByDirection sortDirection) -> System.Collections.Generic.IEnumerable<(TSource item, int rank)>!
+static SuperLinq.SuperEnumerable.Exclude<T>(this System.Collections.Generic.IEnumerable<T>! sequence, System.Range range) -> System.Collections.Generic.IEnumerable<T>!
 static SuperLinq.SuperEnumerable.FullOuterHashJoin<TLeft, TRight, TKey, TResult>(this System.Collections.Generic.IEnumerable<TLeft>! left, System.Collections.Generic.IEnumerable<TRight>! right, System.Func<TLeft, TKey>! leftKeySelector, System.Func<TRight, TKey>! rightKeySelector, System.Func<TLeft, TResult>! leftResultSelector, System.Func<TRight, TResult>! rightResultSelector, System.Func<TLeft, TRight, TResult>! bothResultSelector, System.Collections.Generic.IEqualityComparer<TKey>? comparer = null) -> System.Collections.Generic.IEnumerable<TResult>!
 static SuperLinq.SuperEnumerable.FullOuterHashJoin<TLeft, TRight, TKey>(this System.Collections.Generic.IEnumerable<TLeft>! left, System.Collections.Generic.IEnumerable<TRight>! right, System.Func<TLeft, TKey>! leftKeySelector, System.Func<TRight, TKey>! rightKeySelector, System.Collections.Generic.IEqualityComparer<TKey>? comparer = null) -> System.Collections.Generic.IEnumerable<(TLeft? Left, TRight? Right)>!
 static SuperLinq.SuperEnumerable.FullOuterMergeJoin<TLeft, TRight, TKey, TResult>(this System.Collections.Generic.IEnumerable<TLeft>! left, System.Collections.Generic.IEnumerable<TRight>! right, System.Func<TLeft, TKey>! leftKeySelector, System.Func<TRight, TKey>! rightKeySelector, System.Func<TLeft, TResult>! leftResultSelector, System.Func<TRight, TResult>! rightResultSelector, System.Func<TLeft, TRight, TResult>! bothResultSelector, System.Collections.Generic.IComparer<TKey>? comparer = null) -> System.Collections.Generic.IEnumerable<TResult>!