From b5c5aa8a2f3a435e5b44aac326807e0ce2474285 Mon Sep 17 00:00:00 2001
From: Ts-Pytham <43942761+Ts-Pytham@users.noreply.github.com>
Date: Tue, 27 Dec 2022 15:33:56 -0500
Subject: [PATCH] TryPop and TryPeek methods created

---
 GenericCollectionsExtension/Stack/IStack.cs   | 23 ++++++++++++++
 .../Stack/PriorityStack/IPriorityStack.cs     |  1 +
 .../Stack/PriorityStack/PriorityStack.cs      | 30 ++++++++++++++++++-
 3 files changed, 53 insertions(+), 1 deletion(-)

diff --git a/GenericCollectionsExtension/Stack/IStack.cs b/GenericCollectionsExtension/Stack/IStack.cs
index 7d88e69..8a0b3f8 100644
--- a/GenericCollectionsExtension/Stack/IStack.cs
+++ b/GenericCollectionsExtension/Stack/IStack.cs
@@ -16,6 +16,11 @@ public interface IStack<T> : ICollection<T>
         /// </summary>
         int Capacity { get; }
 
+        /// <summary>
+        /// Gets a value indicating whether the priority stack is empty.
+        /// </summary>
+        bool IsEmpty { get; }
+
         /// <summary>
         /// Returns the element at the top of the stack without removing it.
         /// </summary>
@@ -23,9 +28,27 @@ public interface IStack<T> : ICollection<T>
         T Peek();
 
         /// <summary>
+        /// Returns a value that indicates whether there is an object at the top of the 
+        /// <see cref="IStack{T}"/>, and if one is present, copies it to the result parameter. 
+        /// The object is not removed from the <see cref="IStack{T}"/>.
+        /// </summary>
+        /// <param name="result">If present, the object at the top of the <see cref="IStack{T}"/>; otherwise, the default value of <see cref="{T}"/>.</param>
+        /// <returns><see langword="true"/> if there is an object at the top of the <see cref="IStack{T}"/>; <see langword="false"/> if the <see cref="IStack{T}"/> is empty.</returns>
+        bool TryPeek(out T result);
+
         /// Removes and returns the element at the top of the stack.
         /// </summary>
         /// <returns>The element at the top of the stack.</returns>
         T Pop();
+
+        /// <summary>
+        /// Returns a value that indicates whether there is an object at the top of the 
+        /// <see cref="IStack{T}"/>, and if one is present, copies it to the result parameter,
+        /// and removes it from the <see cref="IStack{T}"/>.
+        /// </summary>
+        /// <param name="result">If present, the object at the top of the <see cref="IStack{T}"/>; otherwise, the default value of <see cref="{T}"/>.</param>
+        /// <returns><see langword="true"/> if there is an object at the top of the <see cref="IStack{T}"/>; <see langword="false"/> if the <see cref="IStack{T}"/> is empty.</returns>
+        bool TryPop(out T result);
+
     }
 }
diff --git a/GenericCollectionsExtension/Stack/PriorityStack/IPriorityStack.cs b/GenericCollectionsExtension/Stack/PriorityStack/IPriorityStack.cs
index b8f10c7..dfabdd2 100644
--- a/GenericCollectionsExtension/Stack/PriorityStack/IPriorityStack.cs
+++ b/GenericCollectionsExtension/Stack/PriorityStack/IPriorityStack.cs
@@ -18,5 +18,6 @@ public interface IPriorityStack<T> : IStack<T>
         /// <param name="item">The element to add to the stack.</param>
         /// <param name="priority">The priority of the element.</param>
         void Push(T item, int priority);
+
     }
 }
diff --git a/GenericCollectionsExtension/Stack/PriorityStack/PriorityStack.cs b/GenericCollectionsExtension/Stack/PriorityStack/PriorityStack.cs
index c703a95..546f761 100644
--- a/GenericCollectionsExtension/Stack/PriorityStack/PriorityStack.cs
+++ b/GenericCollectionsExtension/Stack/PriorityStack/PriorityStack.cs
@@ -24,6 +24,9 @@ public class PriorityStack<T> : IPriorityStack<T>, ICollection<T>, IEnumerable<T
 
         public bool IsReadOnly => false;
 
+        /// <inheritdoc cref="IStack{T}.IsEmpty/>
+        public bool IsEmpty { get => Count == 0; }
+
         /// <summary>
         /// Constructs a new instance of the <see cref="PriorityStack{T}"/> class.
         /// </summary>
@@ -91,10 +94,23 @@ public T Peek()
             return _stack[Count - 1].Value;
         }
 
+        /// <inheritdoc cref="IStack{T}.TryPeek(out T)"/>
+        public bool TryPeek(out T result)
+        {
+            if (!IsEmpty)
+            {
+                result = _stack[Count - 1].Value;
+                return true;
+            }
+
+            result = default;
+            return false;
+        }
+
         /// <inheritdoc cref="IStack{T}.Pop"/>
         public T Pop()
         {
-            if (Count == 0)
+            if (IsEmpty)
                 throw new IndexOutOfRangeException();
 
             var value = _stack[Count - 1].Value;
@@ -102,6 +118,18 @@ public T Pop()
             return value;
         }
 
+        /// <inheritdoc cref="IStack{T}.TryPop(out T)"/>
+        public bool TryPop(out T result)
+        {
+            if (!IsEmpty)
+            {
+                result = Pop();
+                return true;
+            }
+            result = default;
+            return false;
+        }
+
         /// <inheritdoc cref="IPriorityStack{T}.Push(T, int)"/>
         public void Push(T item, int priority)
         {