add some tools

src/Shared/HandyControl_Shared/Tools/Queue/Deque!1.cs

@@ -0,0 +1,345 @@
+// adapted from https://www.c-sharpcorner.com/uploadfile/b942f9/implementing-a-double-ended-queue-or-deque-in-c-sharp/
+
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Threading;
+
+namespace HandyControl.Tools
+{
+    [Serializable]
+    public class Deque<T> : IEnumerable<T>, ICollection
+    {
+        [NonSerialized]
+        private object _syncRoot;
+
+        private List<T> _front;
+
+        private List<T> _back;
+
+        private int _frontDeleted;
+
+        private int _backDeleted;
+
+        public int Capacity => _front.Capacity + _back.Capacity;
+
+        public int Count => _front.Count + _back.Count - _frontDeleted - _backDeleted;
+
+        public bool IsEmpty => Count == 0;
+
+        public IEnumerable<T> Reversed
+        {
+            get
+            {
+                if (_back.Count - _backDeleted > 0)
+                {
+                    for (var i = _back.Count - 1; i >= _backDeleted; i--) yield return _back[i];
+                }
+
+                if (_front.Count - _frontDeleted > 0)
+                {
+                    for (var i = _frontDeleted; i < _front.Count; i++) yield return _front[i];
+                }
+            }
+        }
+
+        public Deque()
+        {
+            _front = new List<T>();
+            _back = new List<T>();
+        }
+
+        public Deque(int capacity)
+        {
+            if (capacity < 0) throw new ArgumentException("Capacity cannot be negative");
+            var temp = capacity / 2;
+            var temp2 = capacity - temp;
+            _front = new List<T>(temp);
+            _back = new List<T>(temp2);
+        }
+
+        public Deque(IEnumerable<T> backCollection) : this(backCollection, null)
+        {
+
+        }
+
+        public Deque(IEnumerable<T> backCollection, IEnumerable<T> frontCollection)
+        {
+            if (backCollection == null && frontCollection == null) throw new ArgumentException("Collections cannot both be null");
+            _front = new List<T>();
+            _back = new List<T>();
+
+            if (backCollection != null)
+            {
+                foreach (var item in backCollection) _back.Add(item);
+            }
+
+            if (frontCollection != null)
+            {
+                foreach (var item in frontCollection) _front.Add(item);
+            }
+        }
+
+        public void AddFirst(T item)
+        {
+            if (_frontDeleted > 0 && _front.Count == _front.Capacity)
+            {
+                _front.RemoveRange(0, _frontDeleted);
+                _frontDeleted = 0;
+            }
+
+            _front.Add(item);
+        }
+
+        public void AddLast(T item)
+        {
+            if (_backDeleted > 0 && _back.Count == _back.Capacity)
+            {
+                _back.RemoveRange(0, _backDeleted);
+                _backDeleted = 0;
+            }
+
+            _back.Add(item);
+        }
+
+        public void AddRangeFirst(IEnumerable<T> range)
+        {
+            if (range == null) return;
+
+            foreach (var item in range) AddFirst(item);
+        }
+
+        public void AddRangeLast(IEnumerable<T> range)
+        {
+            if (range == null) return;
+
+            foreach (var item in range) AddLast(item);
+        }
+
+        public void Clear()
+        {
+            _front.Clear();
+            _back.Clear();
+            _frontDeleted = 0;
+            _backDeleted = 0;
+        }
+
+        public bool Contains(T item)
+        {
+            for (var i = _frontDeleted; i < _front.Count; i++)
+            {
+                if (Equals(_front[i], item)) return true;
+            }
+
+            for (var i = _backDeleted; i < _back.Count; i++)
+            {
+                if (Equals(_back[i], item)) return true;
+            }
+
+            return false;
+        }
+
+        public void CopyTo(T[] array, int index)
+        {
+            if (array == null) throw new ArgumentNullException("Array cannot be null");
+            if (index < 0) throw new ArgumentOutOfRangeException("Index cannot be negative");
+            if (array.Length < index + Count) throw new ArgumentException("Index is invalid");
+            var i = index;
+
+            foreach (var item in this)
+            {
+                array[i++] = item;
+            }
+        }
+
+        public IEnumerator<T> GetEnumerator()
+        {
+            if (_front.Count - _frontDeleted > 0)
+            {
+                for (var i = _front.Count - 1; i >= _frontDeleted; i--) yield return _front[i];
+            }
+
+            if (_back.Count - _backDeleted > 0)
+            {
+                for (var i = _backDeleted; i < _back.Count; i++) yield return _back[i];
+            }
+        }
+
+        public T PeekFirst()
+        {
+            if (_front.Count > _frontDeleted)
+            {
+                return _front[_front.Count - 1];
+            }
+
+            if (_back.Count > _backDeleted)
+            {
+                return _back[_backDeleted];
+            }
+
+            throw new InvalidOperationException("Can't peek at empty Deque");
+        }
+
+        public T PeekLast()
+        {
+            if (_back.Count > _backDeleted)
+            {
+                return _back[_back.Count - 1];
+            }
+
+            if (_front.Count > _frontDeleted)
+            {
+                return _front[_frontDeleted];
+            }
+
+            throw new InvalidOperationException("Can't peek at empty Deque");
+        }
+
+        public T PopFirst()
+        {
+            T result;
+
+            if (_front.Count > _frontDeleted)
+            {
+                result = _front[_front.Count - 1];
+                _front.RemoveAt(_front.Count - 1);
+            }
+            else if (_back.Count > _backDeleted)
+            {
+                result = _back[_backDeleted];
+                _backDeleted++;
+            }
+            else
+            {
+                throw new InvalidOperationException("Can't pop empty Deque");
+            }
+
+            return result;
+        }
+
+
+        public T PopLast()
+        {
+            T result;
+
+            if (_back.Count > _backDeleted)
+            {
+                result = _back[_back.Count - 1];
+                _back.RemoveAt(_back.Count - 1);
+            }
+            else if (_front.Count > _frontDeleted)
+            {
+                result = _front[_frontDeleted];
+                _frontDeleted++;
+            }
+            else
+            {
+                throw new InvalidOperationException("Can't pop empty Deque");
+            }
+
+            return result;
+        }
+
+        public void Reverse()
+        {
+            var temp = _front;
+            _front = _back;
+            _back = temp;
+            var temp2 = _frontDeleted;
+            _frontDeleted = _backDeleted;
+            _backDeleted = temp2;
+        }
+
+        public T[] ToArray()
+        {
+            if (Count == 0) return new T[0];
+            var result = new T[Count];
+            CopyTo(result, 0);
+            return result;
+        }
+
+        public void TrimExcess()
+        {
+            if (_frontDeleted > 0)
+            {
+                _front.RemoveRange(0, _frontDeleted);
+                _frontDeleted = 0;
+            }
+
+            if (_backDeleted > 0)
+            {
+                _back.RemoveRange(0, _backDeleted);
+                _backDeleted = 0;
+            }
+
+            _front.TrimExcess();
+            _back.TrimExcess();
+        }
+
+        public bool TryPeekFirst(out T item)
+        {
+            if (!IsEmpty)
+            {
+                item = PeekFirst();
+                return true;
+            }
+
+            item = default;
+            return false;
+        }
+
+        public bool TryPeekLast(out T item)
+        {
+            if (!IsEmpty)
+            {
+                item = PeekLast();
+                return true;
+            }
+
+            item = default;
+            return false;
+        }
+
+        public bool TryPopFirst(out T item)
+        {
+            if (!IsEmpty)
+            {
+                item = PopFirst();
+                return true;
+            }
+
+            item = default;
+            return false;
+        }
+
+        public bool TryPopLast(out T item)
+        {
+            if (!IsEmpty)
+            {
+                item = PopLast();
+                return true;
+            }
+
+            item = default;
+            return false;
+        }
+
+        bool ICollection.IsSynchronized => false;
+
+        object ICollection.SyncRoot
+        {
+            get
+            {
+                if (_syncRoot == null)
+                {
+                    Interlocked.CompareExchange<object>(ref _syncRoot, new object(), null);
+                }
+                return _syncRoot;
+            }
+        }
+
+        void ICollection.CopyTo(Array array, int index) => CopyTo((T[])array, index);
+
+        IEnumerator IEnumerable.GetEnumerator() => GetEnumerator();
+    }
+}