diff --git a/LibCLCC.NET.NUnit/RefStringTests.cs b/LibCLCC.NET.NUnit/RefStringTests.cs
index 53d9491..6bffb7a 100644
--- a/LibCLCC.NET.NUnit/RefStringTests.cs
+++ b/LibCLCC.NET.NUnit/RefStringTests.cs
@@ -1,74 +1,117 @@
 using LibCLCC.NET.Data;
+using System.Diagnostics;
 
 namespace LibCLCC.NET.NUnit
 {
-    public class RefStringTests
-    {
-        string ori = "/A/B/C//D\\E";
-        [SetUp]
-        public void Setup()
-        {
-        }
-        [Test]
-        public void ParsingTest()
-        {
-            string input = "ASD123.001DEF";
-            RefString A = input;
-            A.Offset = 3;
-            A.Length = 3;
-            {
-                Assert.Multiple(() =>
-                {
-                    Assert.That(A.TryParse(out int v), Is.True);
-                    Assert.That(v, Is.EqualTo(123));
-                });
-            }
+	public class RefStringTests
+	{
+		string ori = "/A/B/C//D\\E";
+		[SetUp]
+		public void Setup()
+		{
+		}
+		[Test]
+		public void SubStringTest()
+		{
+			string str = "This is a sentence. A very long sentence.";
+			RefString rstr = str;
+			var SubString0 = rstr.Substring(0, 4);
+			{
+				string str2 = "This";
+				Assert.That(SubString0 == str2);
+			}
+			{
+				string str2 = "That";
+				Assert.That(SubString0 != str2);
+			}
+			{
+				string str2 = "Tha";
+				Assert.That(SubString0 != str2);
+			}
+			{
+				string str2 = "This is not equal.";
+				Assert.That(SubString0 != str2);
+			}
+			var SubString1 = rstr.Substring(5);
+			{
+				Assert.That(SubString1 == str.Substring(5));
+			}
+			{
+				Assert.That(SubString1 == ((RefString)str).Substring(5));
+			}
+			{
+				Assert.That(SubString1.StartsWith("is"));
+			}
+		}
+		[Test]
+		public void EndsWithTest()
+		{
+			RefString rstr = "new RefString()";
+			RefString R0 = "()";
+			Assert.That(rstr.EndsWith(R0));
+			Assert.That(rstr.Substring(2).EndsWith(R0));
+			Assert.That(rstr.Substring(0,3).EndsWith("ew"));
+		}
+		[Test]
+		public void ParsingTest()
+		{
+			string input = "ASD123.001DEF";
+			RefString A = input;
+			A.Offset = 3;
+			A.Length = 3;
+			{
+				Assert.Multiple(() =>
+				{
+					Assert.That(A.TryParse(out int v), Is.True);
+					Assert.That(v, Is.EqualTo(123));
+				});
+			}
 
-            A.Length += 4;
-            {
-                Assert.Multiple(() =>
-                {
-                    Assert.That(A.TryParse(out float v), Is.True);
-                    Assert.That(v, Is.EqualTo(123.001f));
-                });
-            }
+			A.Length += 4;
+			{
+				Assert.Multiple(() =>
+				{
+					Assert.That(A.TryParse(out float v), Is.True);
+					Assert.That(v, Is.EqualTo(123.001f));
+				});
+			}
 
-            A.Length += 1;
-            {
-                Assert.Multiple(() =>
-                {
-                    Assert.That(A.TryParse(out double v), Is.True);
-                    Assert.That(v, Is.EqualTo(123.001));
-                });
-            }
+			A.Length += 1;
+			{
+				Assert.Multiple(() =>
+				{
+					Assert.That(A.TryParse(out double v), Is.True);
+					Assert.That(v, Is.EqualTo(123.001));
+				});
+			}
 
-            string Testee_00 = "ASD";
-            string Testee_01 = "DEF";
-            A.Offset=0;
-            A.Length=input.Length;
-            Assert.Multiple(() =>
-            {
-                Assert.That(A.StartsWith(Testee_00), Is.True);
-                Assert.That(A.StartsWith(Testee_01), Is.False);
-                Assert.That(A.EndsWith(Testee_00), Is.False);
-                Assert.That(A.EndsWith(Testee_01), Is.True);
-            });
-        }
+			string Testee_00 = "ASD";
+			string Testee_01 = "DEF";
+			A.Offset = 0;
+			A.Length = input.Length;
+			Assert.Multiple(() =>
+			{
+				Assert.That(A.StartsWith(Testee_00), Is.True);
+				Assert.That(A.StartsWith(Testee_01), Is.False);
+				Assert.That(A.EndsWith(Testee_00), Is.False);
+				Assert.That(A.EndsWith(Testee_01), Is.True);
+			});
+		}
 
-        [Test]
-        public void DataTypeTest()
-        {
-            RefString BaseString0 = new RefString(ori, 0, ori.Length);
-            var e = BaseString0.Split('/', '\\');
-            var comp = ori.Split('/', '\\');
-            int i = 0;
-            while (e.MoveNext())
-            {
-                var c = e.Current.FinalizeString();
-                Assert.That(c, Is.EqualTo(comp[i]));
-                i++;
-            }
+		[Test]
+		public void DataTypeTest()
+		{
+			RefString BaseString0 = new RefString(ori, 0, ori.Length);
+			var e = BaseString0.Split('/', '\\');
+			var comp = ori.Split('/', '\\');
+			int i = 0;
+			while (e.MoveNext())
+			{
+				var c = e.Current.FinalizeString();
+				Assert.That(c, Is.EqualTo(comp[i]));
+				i++;
+			}
 
-        }
-    }
+		}
+	}
 }
\ No newline at end of file
diff --git a/LibCLCC.NET/Data/RefString.cs b/LibCLCC.NET/Data/RefString.cs
index ef002b3..d859757 100644
--- a/LibCLCC.NET/Data/RefString.cs
+++ b/LibCLCC.NET/Data/RefString.cs
@@ -1,394 +1,543 @@
 using System;
 using System.Collections;
 using System.Collections.Generic;
+using System.Diagnostics;
 using System.Runtime.CompilerServices;
 using System.Text;
 using System.Xml.XPath;
 
 namespace LibCLCC.NET.Data
 {
-    /// <summary>
-    /// Reference String.
-    /// Use for reduce memory consumption.
-    /// </summary>
-    public struct RefString : IEnumerable<char>, IEnumerable
-    {
-        /// <summary>
-        /// The NULL reference.
-        /// </summary>
-        public readonly static RefString NULL = new RefString() { Ref = null };
-        /// <summary>
-        /// Referred string
-        /// </summary>
-        public string Ref;
-        /// <summary>
-        /// Offset in Ref
-        /// </summary>
-        public int Offset;
-        /// <summary>
-        /// Length of the RefString
-        /// </summary>
-        public int Length;
-        /// <summary>
-        /// Create a RefString.
-        /// </summary>
-        /// <param name="string_value"></param>
-        /// <param name="offset"></param>
-        /// <param name="length"></param>
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public RefString(string string_value, int offset, int length)
-        {
-            Ref = string_value;
-            Offset = offset;
-            Length = length;
-        }
-        /// <summary>
-        /// Get certain character
-        /// </summary>
-        /// <param name="index"></param>
-        /// <returns></returns>
-        public char this[int index]
-        {
-            [MethodImpl(MethodImplOptions.AggressiveInlining)]
-            get
-            {
-                return Ref[index + Offset];
-            }
-        }
+	/// <summary>
+	/// Reference String.
+	/// Use for reduce memory consumption.
+	/// </summary>
+	public struct RefString : IEnumerable<char>, IEnumerable
+	{
+		/// <summary>
+		/// The NULL reference.
+		/// </summary>
+		public readonly static RefString NULL = new RefString() { Ref = null };
+		/// <summary>
+		/// Referred string
+		/// </summary>
+		public string Ref;
+		/// <summary>
+		/// Offset in Ref
+		/// </summary>
+		public int Offset;
+		/// <summary>
+		/// Length of the RefString
+		/// </summary>
+		public int Length;
+		/// <summary>
+		/// Create a RefString.
+		/// </summary>
+		/// <param name="string_value"></param>
+		/// <param name="offset"></param>
+		/// <param name="length"></param>
+		[MethodImpl(MethodImplOptions.AggressiveInlining)]
+		public RefString(string string_value, int offset, int length)
+		{
+			Ref = string_value;
+			Offset = offset;
+			Length = length;
+		}
+		/// <summary>
+		/// Get certain character
+		/// </summary>
+		/// <param name="index"></param>
+		/// <returns></returns>
+		public char this[int index]
+		{
+			[MethodImpl(MethodImplOptions.AggressiveInlining)]
+			get
+			{
+				return Ref[index + Offset];
+			}
+		}
 
-        /// <summary>
-        /// Treat it as a read-only stan
-        /// </summary>
-        /// <returns></returns>
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public ReadOnlySpan<char> AsReadOnlySpan() => (ReadOnlySpan<char>)this;
-        /// <summary>
-        /// Convert a string to a RefString
-        /// </summary>
-        /// <param name="s"></param>
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public static implicit operator RefString(string s) => new RefString { Ref = s, Offset = 0, Length = s.Length };
-        /// <summary>
-        /// Convert a RefString to ReadOnlySpan
-        /// </summary>
-        /// <param name="s"></param>
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public static implicit operator ReadOnlySpan<char>(RefString s)
-        {
-            if (s.Offset + s.Length > s.Ref.Length)
-            {
-                throw new IndexOutOfRangeException();
-            }
-            return s.Ref.AsSpan(s.Offset, s.Length);
-        }
-        /// <summary>
-        /// If the referred string is null.
-        /// </summary>
-        /// <returns></returns>
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public readonly bool IsNull() => Ref == null;
-        /// <summary>
-        /// If the referred string is not null.
-        /// </summary>
-        /// <returns></returns>
+		/// <summary>
+		/// Treat it as a read-only stan
+		/// </summary>
+		/// <returns></returns>
+		[MethodImpl(MethodImplOptions.AggressiveInlining)]
+		public ReadOnlySpan<char> AsReadOnlySpan() => (ReadOnlySpan<char>)this;
+		/// <summary>
+		/// Convert a string to a RefString
+		/// </summary>
+		/// <param name="s"></param>
+		[MethodImpl(MethodImplOptions.AggressiveInlining)]
+		public static implicit operator RefString(string s) => new RefString { Ref = s, Offset = 0, Length = s.Length };
+		/// <summary>
+		/// Convert a RefString to ReadOnlySpan
+		/// </summary>
+		/// <param name="s"></param>
+		[MethodImpl(MethodImplOptions.AggressiveInlining)]
+		public static implicit operator ReadOnlySpan<char>(RefString s)
+		{
+			if (s.Offset + s.Length > s.Ref.Length)
+			{
+				throw new IndexOutOfRangeException();
+			}
+			return s.Ref.AsSpan(s.Offset, s.Length);
+		}
+		/// <summary>
+		/// If the referred string is null.
+		/// </summary>
+		/// <returns></returns>
+		[MethodImpl(MethodImplOptions.AggressiveInlining)]
+		public readonly bool IsNull() => Ref == null;
+		/// <summary>
+		/// If the referred string is not null.
+		/// </summary>
+		/// <returns></returns>
 
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public readonly bool IsNotNull() => Ref != null;
-        /// <summary>
-        /// Move the offset of the string. The length will be adjusted as well.
-        /// </summary>
-        /// <param name="L"></param>
-        /// <param name="R"></param>
-        /// <returns></returns>
-        /// <exception cref="IndexOutOfRangeException"></exception>
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public static RefString operator +(RefString L, int R)
-        {
-            RefString result = L;
-            result.Ref = L.Ref;
-            result.Offset += R;
-            result.Length -= R;
-            if (result.Length < 0) throw new IndexOutOfRangeException();
-            return result;
-        }
-        /// <summary>
-        /// Move the offset of the string. The length will be adjusted as well.
-        /// </summary>
-        /// <param name="L"></param>
-        /// <param name="R"></param>
-        /// <returns></returns>
-        /// <exception cref="IndexOutOfRangeException"></exception>
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public static RefString operator -(RefString L, int R)
-        {
-            RefString result = L;
-            result.Ref = L.Ref;
-            result.Offset -= R;
-            result.Length += R;
-            if (result.Offset < 0) throw new IndexOutOfRangeException();
-            return result;
-        }
-        /// <summary>
-        /// Check if equal to a string.
-        /// </summary>
-        /// <param name="L"></param>
-        /// <param name="R"></param>
-        /// <returns></returns>
-        /// <exception cref="IndexOutOfRangeException"></exception>
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public static bool operator ==(RefString L, string R)
-        {
+		[MethodImpl(MethodImplOptions.AggressiveInlining)]
+		public readonly bool IsNotNull() => Ref != null;
+		/// <summary>
+		/// Move the offset of the string. The length will be adjusted as well.
+		/// </summary>
+		/// <param name="L"></param>
+		/// <param name="R"></param>
+		/// <returns></returns>
+		/// <exception cref="IndexOutOfRangeException"></exception>
+		[MethodImpl(MethodImplOptions.AggressiveInlining)]
+		public static RefString operator +(RefString L, int R)
+		{
+			RefString result = L;
+			result.Ref = L.Ref;
+			result.Offset += R;
+			result.Length -= R;
+			if (result.Length < 0) throw new IndexOutOfRangeException();
+			return result;
+		}
+		/// <summary>
+		/// Move the offset of the string. The length will be adjusted as well.
+		/// </summary>
+		/// <param name="L"></param>
+		/// <param name="R"></param>
+		/// <returns></returns>
+		/// <exception cref="IndexOutOfRangeException"></exception>
+		[MethodImpl(MethodImplOptions.AggressiveInlining)]
+		public static RefString operator -(RefString L, int R)
+		{
+			RefString result = L;
+			result.Ref = L.Ref;
+			result.Offset -= R;
+			result.Length += R;
+			if (result.Offset < 0) throw new IndexOutOfRangeException();
+			return result;
+		}
+		/// <summary>
+		/// Check if equal to a string.
+		/// </summary>
+		/// <param name="L"></param>
+		/// <param name="R"></param>
+		/// <returns></returns>
+		/// <exception cref="IndexOutOfRangeException"></exception>
+		[MethodImpl(MethodImplOptions.AggressiveInlining)]
+		public static bool operator ==(RefString L, string R)
+		{
 
-            var i = L.Ref.IndexOf(R, L.Offset);
-            var Len = R.Length;
-            return (i == 0 && Len == L.Length);
-        }
-        /// <summary>
-        /// 
-        /// </summary>
-        /// <param name="R"></param>
-        /// <returns></returns>
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public bool StartsWith(string R)
-        {
-            return this.Ref.IndexOf(R, Offset) == 0;
-        }
-        /// <summary>
-        /// 
-        /// </summary>
-        /// <param name="R"></param>
-        /// <param name="_offset"></param>
-        /// <returns></returns>
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public bool StartsWith(string R, int _offset)
-        {
-            return this.Ref.IndexOf(R, Offset + _offset) == 0;
-        }
-        char ToOtherCase(char c)
-        {
-            if (c >= 'A' && c <= 'Z')
-            {
-                return (char)(c - 'A' + 'a');
-            }
-            if (c >= 'a' && c <= 'z')
-            {
-                return (char)(c - +'A' - 'a');
-            }
-            return c;
-        }
-        /// <summary>
-        /// 
-        /// </summary>
-        /// <param name="R"></param>
-        /// <param name="_offset"></param>
-        /// <param name="CaseIrrelevant"></param>
-        /// <returns></returns>
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public bool StartsWith(string R, int _offset, bool CaseIrrelevant)
-        {
-            if (CaseIrrelevant)
-            {
+			var startI = L.Ref.IndexOf(R, L.Offset) - L.Offset;
+			var Len = R.Length;
+			if (startI == 0 && Len == L.Length)
+			{
+				for (int i = 0; i < Len; i++)
+				{
+					if (L[i] != R[i])
+					{
+						return false;
+					}
+				}
+				return true;
+			}
+			return false;
+		}
+		/// <summary>
+		/// Compare 2 RefString even if the internal Referenced strings are different.
+		/// </summary>
+		/// <param name="L"></param>
+		/// <param name="R"></param>
+		/// <returns></returns>
+		[MethodImpl(MethodImplOptions.AggressiveInlining)]
+		public static bool operator ==(RefString L, RefString R)
+		{
 
-                for (int i = 0; i < R.Length; i++)
-                {
-                    char v = R[i];
-                    if (Ref[Offset + _offset + i] != v && Ref[Offset + _offset + i] != ToOtherCase(v))
-                    {
-                        return false;
-                    }
-                }
-                return true;
-            }
-            else
-            {
-                return this.Ref.IndexOf(R, Offset + _offset) == 0;
-            }
-        }
-        /// <summary>
-        /// 
-        /// </summary>
-        /// <param name="R"></param>
-        /// <returns></returns>
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public bool EndsWith(string R)
-        {
-            return this.Ref.IndexOf(R, Offset) == (Length - R.Length);
-        }
-        /// <summary>
-        /// Move the offset of the string. The length will be adjusted as well.
-        /// </summary>
-        /// <param name="L"></param>
-        /// <param name="R"></param>
-        /// <returns></returns>
-        /// <exception cref="IndexOutOfRangeException"></exception>
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public static bool operator !=(RefString L, string R)
-        {
-            var i = L.Ref.IndexOf(R, L.Offset);
-            var Len = R.Length;
-            return (i != 0 || Len != L.Length);
-        }
-        /// <summary>
-        /// Retrieves a substring. The substring has a given start position and continues to the end of the RefString.
-        /// </summary>
-        /// <param name="StartIndex"></param>
-        /// <returns></returns>
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public readonly RefString Substring(int StartIndex)
-        {
-            return this + StartIndex;
-        }
-        /// <summary>
-        /// Retrieves a substring. The substring has a given start position and has a given length.
-        /// </summary>
-        /// <param name="StartIndex"></param>
-        /// <param name="SubStringLength"></param>
-        /// <returns></returns>
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public readonly RefString Substring(int StartIndex, int SubStringLength)
-        {
-            var r = this + StartIndex;
-            r.Length = SubStringLength;
-            return r;
-        }
-        /// <summary>
-        /// Returns a zero-based index of the first appearance of a given char within this sturct. 
-        /// The method returns -1 if the target is not found in this instance.
-        /// </summary>
-        /// <param name="c"></param>
-        /// <returns></returns>
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public readonly int IndexOf(char c)
-        {
-            return Ref.IndexOf(c, Offset, Length);
-        }
-        /// <summary>
-        /// Returns a zero-based index of the first appearance of a given string within this sturct. 
-        /// The method returns -1 if the target is not found in this instance.
-        /// </summary>
-        /// <param name="str"></param>
-        /// <returns></returns>
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public readonly int IndexOf(string str)
-        {
-            return Ref.IndexOf(str, Offset, Length);
-        }
-        /// <summary>
-        /// Returns a zero-based index of the first appearance of a given char within this sturct. 
-        /// The method returns -1 if the target is not found in this instance.
-        /// The search starts at a given position.
-        /// </summary>
-        /// <param name="c"></param>
-        /// <param name="offset"></param>
-        /// <returns></returns>
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public readonly int IndexOf(char c, int offset)
-        {
-            return Ref.IndexOf(c, Offset + offset, Length);
-        }
-        /// <summary>
-        /// Returns a zero-based index of the first appearance of a given char within this sturct. 
-        /// The method returns -1 if the target is not found in this instance.
-        /// The search starts at a given position.
-        /// </summary>
-        /// <param name="c"></param>
-        /// <param name="offset"></param>
-        /// <param name="count"></param>
-        /// <returns></returns>
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public readonly int IndexOf(char c, int offset, int count)
-        {
-            return Ref.IndexOf(c, Offset + offset, Math.Min(Length, count));
-        }
-        /// <summary>
-        /// Returns a zero-based index of the first appearance of a given string within this sturct. 
-        /// The method returns -1 if the target is not found in this instance.
-        /// The search starts at a given position.
-        /// </summary>
-        /// <param name="str"></param>
-        /// <param name="offset"></param>
-        /// <returns></returns>
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public readonly int IndexOf(string str, int offset)
-        {
-            return Ref.IndexOf(str, Offset + offset, Length);
-        }
-        /// <summary>
-        /// Returns a zero-based index of the first appearance of a given string within this sturct. 
-        /// The method returns -1 if the target is not found in this instance.
-        /// The search starts at a given position.
-        /// </summary>
-        /// <param name="str"></param>
-        /// <param name="offset"></param>
-        /// <param name="count"></param>
-        /// <returns></returns>
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public readonly int IndexOf(string str, int offset, int count)
-        {
-            return Ref.IndexOf(str, Offset + offset, Math.Min(Length, count));
-        }
-        /// <summary>
-        /// Iterate through characters in range [offset..offset+length].
-        /// </summary>
-        /// <returns></returns>
+			var Len = R.Length;
+			if (Len == L.Length)
+			{
+				for (int i = 0; i < Len; i++)
+				{
+					if (L[i] != R[i])
+					{
+						return false;
+					}
+				}
+				return true;
+			}
+			return false;
+		}
+		/// <summary>
+		/// Compare 2 RefString even if the internal Referenced strings are different.
+		/// </summary>
+		/// <param name="L"></param>
+		/// <param name="R"></param>
+		/// <returns></returns>
+		[MethodImpl(MethodImplOptions.AggressiveInlining)]
+		public static bool operator !=(RefString L, RefString R)
+		{
+			return !(L == R);
+		}
+		/// <summary>
+		/// 
+		/// </summary>
+		/// <param name="R"></param>
+		/// <returns></returns>
+		[MethodImpl(MethodImplOptions.AggressiveInlining)]
+		public bool StartsWith(string R)
+		{
+			return (Ref.IndexOf(R, Offset) - Offset) == 0;
+		}
+		/// <summary>
+		/// 
+		/// </summary>
+		/// <param name="R"></param>
+		/// <param name="_offset"></param>
+		/// <returns></returns>
+		[MethodImpl(MethodImplOptions.AggressiveInlining)]
+		public bool StartsWith(string R, int _offset)
+		{
+			return (Ref.IndexOf(R, Offset + _offset) - Offset) == 0;
+		}
+		char ToOtherCase(char c)
+		{
+			if (c >= 'A' && c <= 'Z')
+			{
+				return (char)(c - 'A' + 'a');
+			}
+			if (c >= 'a' && c <= 'z')
+			{
+				return (char)(c - +'A' - 'a');
+			}
+			return c;
+		}
+		/// <summary>
+		/// 
+		/// </summary>
+		/// <param name="R"></param>
+		/// <param name="_offset"></param>
+		/// <param name="CaseIrrelevant"></param>
+		/// <returns></returns>
+		[MethodImpl(MethodImplOptions.AggressiveInlining)]
+		public bool StartsWith(string R, int _offset, bool CaseIrrelevant)
+		{
+			if (CaseIrrelevant)
+			{
 
-        public IEnumerator<char> GetEnumerator()
-        {
-            return iterate();
-        }
-        /// <summary>
-        /// Split the string.
-        /// </summary>
-        /// <param name="splitters"></param>
-        /// <returns></returns>
-        public IEnumerator<RefString> Split(params char[] splitters)
-        {
-            RefString result = new RefString(this.Ref, Offset, 0);
-            for (int i = Offset; i < Length; i++)
-            {
-                var item = this.Ref[i];
-                foreach (var tester in splitters)
-                {
-                    if (item == tester)
-                    {
-                        yield return result;
-                        result = new RefString(this.Ref, i + 1, 0);
-                        goto SKIP;
-                    }
-                }
-                result.Length++;
-            SKIP:;
-            }
-            yield return result;
-        }
-        /// <summary>
-        /// Split the string.
-        /// </summary>
-        /// <param name="splitters"></param>
-        /// <returns></returns>
-        public RefStringSplitQuery SplitQuery(params char[] splitters)
-        {
-            return new RefStringSplitQuery { query = Split(splitters) };
-        }
-        IEnumerator<char> iterate()
-        {
-            for (int i = Offset; i < Length; i++)
-            {
-                yield return Ref[i];
-            }
-            yield break;
-        }
-        IEnumerator IEnumerable.GetEnumerator()
-        {
-            return iterate();
-        }
-        /// <summary>
-        /// Convert to a new string.
-        /// </summary>
-        /// <returns></returns>
-        public string FinalizeString()
-        {
-            return Ref[Offset..(Offset + Length)];
-        }
-    }
+				for (int i = 0; i < R.Length; i++)
+				{
+					char v = R[i];
+					if (Ref[Offset + _offset + i] != v && Ref[Offset + _offset + i] != ToOtherCase(v))
+					{
+						return false;
+					}
+				}
+				return true;
+			}
+			else
+			{
+				return this.Ref.IndexOf(R, Offset + _offset) - Offset == 0;
+			}
+		}
+		/// <summary>
+		/// 
+		/// </summary>
+		/// <param name="R"></param>
+		/// <returns></returns>
+		[MethodImpl(MethodImplOptions.AggressiveInlining)]
+		public bool EndsWith(string R)
+		{
+			if (R.Length > Length) return false;
+			return this.IndexOf(R, Length - R.Length) == Length - R.Length;
+		}
+		/// <summary>
+		/// 
+		/// </summary>
+		/// <param name="R"></param>
+		/// <returns></returns>
+		[MethodImpl(MethodImplOptions.AggressiveInlining)]
+		public bool EndsWith(RefString R)
+		{
+			if (R.Length > Length) return false;
+			return IndexOfSL(R, Length - R.Length) == Length - R.Length;
+		}
+		/// <summary>
+		/// The opposite of ==
+		/// </summary>
+		/// <param name="L"></param>
+		/// <param name="R"></param>
+		/// <returns></returns>
+		/// <exception cref="IndexOutOfRangeException"></exception>
+		[MethodImpl(MethodImplOptions.AggressiveInlining)]
+		public static bool operator !=(RefString L, string R)
+		{
+			return !(L == R);
+		}
+		/// <summary>
+		/// Retrieves a substring. The substring has a given start position and continues to the end of the RefString.
+		/// </summary>
+		/// <param name="StartIndex"></param>
+		/// <returns></returns>
+		[MethodImpl(MethodImplOptions.AggressiveInlining)]
+		public readonly RefString Substring(int StartIndex)
+		{
+			return this + StartIndex;
+		}
+		/// <summary>
+		/// Retrieves a substring. The substring has a given start position and has a given length.
+		/// </summary>
+		/// <param name="StartIndex"></param>
+		/// <param name="SubStringLength"></param>
+		/// <returns></returns>
+		[MethodImpl(MethodImplOptions.AggressiveInlining)]
+		public readonly RefString Substring(int StartIndex, int SubStringLength)
+		{
+			var r = this + StartIndex;
+			if (r.Length < SubStringLength)
+			{
+				throw new ArgumentOutOfRangeException(nameof(SubStringLength));
+			}
+			r.Length = SubStringLength;
+			return r;
+		}
+		/// <summary>
+		/// Returns a zero-based index of the first appearance of a given char within this sturct. 
+		/// The method returns -1 if the target is not found in this instance.
+		/// </summary>
+		/// <param name="c"></param>
+		/// <returns></returns>
+		[MethodImpl(MethodImplOptions.AggressiveInlining)]
+		public readonly int IndexOf(char c)
+		{
+			return Ref.IndexOf(c, Offset, Length) - Offset;
+		}
+		/// <summary>
+		/// Returns a zero-based index of the first appearance of a given string within this sturct. 
+		/// The method returns -1 if the target is not found in this instance.
+		/// </summary>
+		/// <param name="str"></param>
+		/// <returns></returns>
+		[MethodImpl(MethodImplOptions.AggressiveInlining)]
+		public readonly int IndexOf(string str)
+		{
+			return Ref.IndexOf(str, Offset, Length) - Offset;
+		}
+		/// <summary>
+		/// Will create Reference Object!
+		/// </summary>
+		/// <param name="str"></param>
+		/// <returns></returns>
+		[MethodImpl(MethodImplOptions.AggressiveInlining)]
+		public readonly int IndexOf(RefString str)
+		{
+			return Ref.IndexOf(str.FinalizeString(), Offset, Length) - Offset;
+		}
+		/// <summary>
+		/// Will create Reference Object!
+		/// </summary>
+		/// <param name="str"></param>
+		/// <param name="Offset"></param>
+		/// <returns></returns>
+		[MethodImpl(MethodImplOptions.AggressiveInlining)]
+		public readonly int IndexOf(RefString str, int Offset)
+		{
+			return IndexOf(str.FinalizeString(), Offset);
+		}
+		/// <summary>
+		/// Slow version of IndexOf, but use less memory.
+		/// </summary>
+		/// <param name="str"></param>
+		/// <returns></returns>
+		public readonly int IndexOfSL(RefString str)
+		{
+			for (int i = 0; i < this.Length - str.Length; i++)
+			{
+				var L = this + i;
+				L.Length = str.Length;
+				if (L == str)
+				{
+					return i;
+				}
+			}
+			return -1;
+		}
+		/// <summary>
+		/// Slow version of IndexOf, but use less memory.
+		/// </summary>
+		/// <param name="str"></param>
+		/// <param name="Offset"></param>
+		/// <returns></returns>
+		public readonly int IndexOfSL(RefString str, int Offset)
+		{
+			for (int i = Offset; i <= Length - str.Length; i++)
+			{
+				var L = this + i;
+				L.Length = str.Length;
+				if (L == str)
+				{
+					return i;
+				}
+			}
+			return -1;
+		}
+		/// <summary>
+		/// Returns a zero-based index of the first appearance of a given char within this sturct. 
+		/// The method returns -1 if the target is not found in this instance.
+		/// The search starts at a given position.
+		/// </summary>
+		/// <param name="c"></param>
+		/// <param name="offset"></param>
+		/// <returns></returns>
+		[MethodImpl(MethodImplOptions.AggressiveInlining)]
+		public readonly int IndexOf(char c, int offset)
+		{
+			return Ref.IndexOf(c, Offset + offset, Length) - Offset;
+		}
+		/// <summary>
+		/// Returns a zero-based index of the first appearance of a given char within this sturct. 
+		/// The method returns -1 if the target is not found in this instance.
+		/// The search starts at a given position.
+		/// </summary>
+		/// <param name="c"></param>
+		/// <param name="offset"></param>
+		/// <param name="count"></param>
+		/// <returns></returns>
+		[MethodImpl(MethodImplOptions.AggressiveInlining)]
+		public readonly int IndexOf(char c, int offset, int count)
+		{
+			return Ref.IndexOf(c, Offset + offset, Math.Min(Length, count)) - Offset;
+		}
+		/// <summary>
+		/// Returns a zero-based index of the first appearance of a given string within this sturct. 
+		/// The method returns -1 if the target is not found in this instance.
+		/// The search starts at a given position.
+		/// </summary>
+		/// <param name="str"></param>
+		/// <param name="offset"></param>
+		/// <returns></returns>
+		[MethodImpl(MethodImplOptions.AggressiveInlining)]
+		public readonly int IndexOf(string str, int offset)
+		{
+			int startIndex = Offset + offset;
+			return Ref.IndexOf(str, startIndex, Length - offset) - Offset;
+		}
+		/// <summary>
+		/// Returns a zero-based index of the first appearance of a given string within this sturct. 
+		/// The method returns -1 if the target is not found in this instance.
+		/// The search starts at a given position.
+		/// </summary>
+		/// <param name="str"></param>
+		/// <param name="offset"></param>
+		/// <param name="count"></param>
+		/// <returns></returns>
+		[MethodImpl(MethodImplOptions.AggressiveInlining)]
+		public readonly int IndexOf(string str, int offset, int count)
+		{
+			return Ref.IndexOf(str, Offset + offset, Math.Min(Length, count)) - Offset;
+		}
+		/// <summary>
+		/// Iterate through characters in range [offset..offset+length].
+		/// </summary>
+		/// <returns></returns>
+
+		public IEnumerator<char> GetEnumerator()
+		{
+			return iterate();
+		}
+		/// <summary>
+		/// Split the string.
+		/// </summary>
+		/// <param name="splitters"></param>
+		/// <returns></returns>
+		public IEnumerator<RefString> Split(params char[] splitters)
+		{
+			RefString result = new RefString(this.Ref, Offset, 0);
+			for (int i = Offset; i < Length; i++)
+			{
+				var item = this.Ref[i];
+				foreach (var tester in splitters)
+				{
+					if (item == tester)
+					{
+						yield return result;
+						result = new RefString(this.Ref, i + 1, 0);
+						goto SKIP;
+					}
+				}
+				result.Length++;
+			SKIP:;
+			}
+			yield return result;
+		}
+		/// <summary>
+		/// Split the string.
+		/// </summary>
+		/// <param name="splitters"></param>
+		/// <returns></returns>
+		public RefStringSplitQuery SplitQuery(params char[] splitters)
+		{
+			return new RefStringSplitQuery { query = Split(splitters) };
+		}
+		IEnumerator<char> iterate()
+		{
+			for (int i = Offset; i < Length; i++)
+			{
+				yield return Ref[i];
+			}
+			yield break;
+		}
+		IEnumerator IEnumerable.GetEnumerator()
+		{
+			return iterate();
+		}
+		/// <summary>
+		/// Convert to a new string.
+		/// </summary>
+		/// <returns></returns>
+		public string FinalizeString()
+		{
+			return Ref[Offset..(Offset + Length)];
+		}
+		/// <summary>
+		/// Equality to any obj.
+		/// </summary>
+		/// <param name="obj"></param>
+		/// <returns></returns>
+		public override bool Equals(object obj)
+		{
+			if (obj is string s)
+			{
+				return this == s;
+			}
+			return base.Equals(obj);
+		}
+		/// <summary>
+		/// Get the hash code of the RefString.
+		/// </summary>
+		/// <returns></returns>
+		public override int GetHashCode()
+		{
+			return base.GetHashCode();
+		}
+		/// <summary>
+		/// ToString via FinalizeString().
+		/// </summary>
+		/// <returns></returns>
+		public override string ToString()
+		{
+			return FinalizeString();
+		}
+	}
 }
diff --git a/LibCLCC.NET/LibCLCC.NET.csproj b/LibCLCC.NET/LibCLCC.NET.csproj
index be1e274..348bfb4 100644
--- a/LibCLCC.NET/LibCLCC.NET.csproj
+++ b/LibCLCC.NET/LibCLCC.NET.csproj
@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <TargetFramework>netstandard2.1</TargetFramework>
-    <Version>$(VersionPrefix)1.29.30.0</Version>
+    <Version>$(VersionPrefix)1.30.31.0</Version>
     <PackageLicenseFile>LICENSE.txt</PackageLicenseFile>
     <PackageRequireLicenseAcceptance>False</PackageRequireLicenseAcceptance>
     <PackageReadmeFile>README.md</PackageReadmeFile>