Fixing issues as per suggestions from @kevcunnane

src/Microsoft.SqlTools.ServiceLayer/Workspace/Contracts/BufferPosition.cs

@@ -0,0 +1,110 @@
+//
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+//
+
+using System.Diagnostics;
+
+namespace Microsoft.SqlTools.ServiceLayer.Workspace.Contracts
+{
+    /// <summary>
+    /// Provides details about a position in a file buffer.  All
+    /// positions are expressed in 1-based positions (i.e. the
+    /// first line and column in the file is position 1,1).
+    /// </summary>
+    [DebuggerDisplay("Position = {Line}:{Column}")]
+    public class BufferPosition
+    {
+        #region Properties
+
+        /// <summary>
+        /// Provides an instance that represents a position that has not been set.
+        /// </summary>
+        public static readonly BufferPosition None = new BufferPosition(-1, -1);
+
+        /// <summary>
+        /// Gets the line number of the position in the buffer.
+        /// </summary>
+        public int Line { get; private set; }
+
+        /// <summary>
+        /// Gets the column number of the position in the buffer.
+        /// </summary>
+        public int Column { get; private set; }
+
+        #endregion
+
+        #region Constructors
+
+        /// <summary>
+        /// Creates a new instance of the BufferPosition class.
+        /// </summary>
+        /// <param name="line">The line number of the position.</param>
+        /// <param name="column">The column number of the position.</param>
+        public BufferPosition(int line, int column)
+        {
+            this.Line = line;
+            this.Column = column;
+        }
+
+        #endregion
+
+        #region Public Methods
+
+        /// <summary>
+        /// Compares two instances of the BufferPosition class.
+        /// </summary>
+        /// <param name="obj">The object to which this instance will be compared.</param>
+        /// <returns>True if the positions are equal, false otherwise.</returns>
+        public override bool Equals(object obj)
+        {
+            if (!(obj is BufferPosition))
+            {
+                return false;
+            }
+
+            BufferPosition other = (BufferPosition)obj;
+
+            return
+                this.Line == other.Line &&
+                this.Column == other.Column;
+        }
+
+        /// <summary>
+        /// Calculates a unique hash code that represents this instance.
+        /// </summary>
+        /// <returns>A hash code representing this instance.</returns>
+        public override int GetHashCode()
+        {
+            return this.Line.GetHashCode() ^ this.Column.GetHashCode();
+        }
+
+        /// <summary>
+        /// Compares two positions to check if one is greater than the other.
+        /// </summary>
+        /// <param name="positionOne">The first position to compare.</param>
+        /// <param name="positionTwo">The second position to compare.</param>
+        /// <returns>True if positionOne is greater than positionTwo.</returns>
+        public static bool operator >(BufferPosition positionOne, BufferPosition positionTwo)
+        {
+            return
+                (positionOne != null && positionTwo == null) ||
+                (positionOne.Line > positionTwo.Line) ||
+                (positionOne.Line == positionTwo.Line &&
+                 positionOne.Column > positionTwo.Column);
+        }
+
+        /// <summary>
+        /// Compares two positions to check if one is less than the other.
+        /// </summary>
+        /// <param name="positionOne">The first position to compare.</param>
+        /// <param name="positionTwo">The second position to compare.</param>
+        /// <returns>True if positionOne is less than positionTwo.</returns>
+        public static bool operator <(BufferPosition positionOne, BufferPosition positionTwo)
+        {
+            return positionTwo > positionOne;
+        }
+
+        #endregion
+    }
+}