source: branches/2893_BNLR/HeuristicLab.ExtLibs/HeuristicLab.AvalonEdit/5.0.1/AvalonEdit-5.0.1/Utils/StringSegment.cs

// Copyright (c) 2014 AlphaSierraPapa for the SharpDevelop Team
// 
// Permission is hereby granted, free of charge, to any person obtaining a copy of this
// software and associated documentation files (the "Software"), to deal in the Software
// without restriction, including without limitation the rights to use, copy, modify, merge,
// publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons
// to whom the Software is furnished to do so, subject to the following conditions:
// 
// The above copyright notice and this permission notice shall be included in all copies or
// substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
// FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.

using System;

namespace ICSharpCode.AvalonEdit.Utils
{
  /// <summary>
  /// Represents a string with a segment.
  /// Similar to System.ArraySegment&lt;T&gt;, but for strings instead of arrays.
  /// </summary>
  public struct StringSegment : IEquatable<StringSegment>
  {
    readonly string text;
    readonly int offset;
    readonly int count;
    
    /// <summary>
    /// Creates a new StringSegment.
    /// </summary>
    public StringSegment(string text, int offset, int count)
    {
      if (text == null)
        throw new ArgumentNullException("text");
      if (offset < 0 || offset > text.Length)
        throw new ArgumentOutOfRangeException("offset");
      if (offset + count > text.Length)
        throw new ArgumentOutOfRangeException("count");
      this.text = text;
      this.offset = offset;
      this.count = count;
    }
    
    /// <summary>
    /// Creates a new StringSegment.
    /// </summary>
    public StringSegment(string text)
    {
      if (text == null)
        throw new ArgumentNullException("text");
      this.text = text;
      this.offset = 0;
      this.count = text.Length;
    }
    
    /// <summary>
    /// Gets the string used for this segment.
    /// </summary>
    public string Text {
      get { return text; }
    }
    
    /// <summary>
    /// Gets the start offset of the segment with the text.
    /// </summary>
    public int Offset {
      get { return offset; }
    }
    
    /// <summary>
    /// Gets the length of the segment.
    /// </summary>
    public int Count {
      get { return count; }
    }
    
    #region Equals and GetHashCode implementation
    /// <inheritdoc/>
    public override bool Equals(object obj)
    {
      if (obj is StringSegment)
        return Equals((StringSegment)obj); // use Equals method below
      else
        return false;
    }
    
    /// <inheritdoc/>
    public bool Equals(StringSegment other)
    {
      // add comparisions for all members here
      return object.ReferenceEquals(this.text, other.text) && offset == other.offset && count == other.count;
    }
    
    /// <inheritdoc/>
    public override int GetHashCode()
    {
      return text.GetHashCode() ^ offset ^ count;
    }
    
    /// <summary>
    /// Equality operator.
    /// </summary>
    public static bool operator ==(StringSegment left, StringSegment right)
    {
      return left.Equals(right);
    }
    
    /// <summary>
    /// Inequality operator.
    /// </summary>
    public static bool operator !=(StringSegment left, StringSegment right)
    {
      return !left.Equals(right);
    }
    #endregion
  }
}