diff --git a/dotnet/Selfie.Lib/guts/Slice.cs b/dotnet/Selfie.Lib/guts/Slice.cs
deleted file mode 100644
index 6cbdd3a7..00000000
--- a/dotnet/Selfie.Lib/guts/Slice.cs
+++ /dev/null
@@ -1,120 +0,0 @@
-using System;
-using System.Runtime.CompilerServices;
-
-[assembly: InternalsVisibleTo("Selfie.Lib.Tests")]
-
-namespace DiffPlug.Selfie.Guts;
-internal class Slice {
-  private string Base { get; }
-  private int StartIndex { get; }
-  private int EndIndex { get; }
-
-  public Slice(string @base, int startIndex = 0, int endIndex = -1) {
-    Base = @base;
-    StartIndex = startIndex;
-    EndIndex = endIndex == -1 ? @base.Length : endIndex;
-
-    if (StartIndex < 0 || StartIndex > EndIndex || EndIndex > Base.Length) {
-      throw new ArgumentOutOfRangeException(nameof(startIndex), "Start and end indices must be within the base string's bounds.");
-    }
-  }
-
-  public int Length => EndIndex - StartIndex;
-
-  public char this[int index] => Base[StartIndex + index];
-
-  public Slice SubSequence(int start, int end) {
-    return new Slice(Base, StartIndex + start, StartIndex + end);
-  }
-
-  public Slice Trim() {
-    int start = 0, end = Length;
-    while (start < end && char.IsWhiteSpace(this[start])) start++;
-    while (start < end && char.IsWhiteSpace(this[end - 1])) end--;
-
-    return start > 0 || end < Length ? SubSequence(start, end) : this;
-  }
-
-  public override string ToString() {
-    return Base.Substring(StartIndex, Length);
-  }
-
-  public bool SameAs(Slice other) {
-    if (Length != other.Length) return false;
-
-    for (int i = 0; i < Length; i++) {
-      if (this[i] != other[i]) return false;
-    }
-
-    return true;
-  }
-
-  public bool SameAs(string other) {
-    if (Length != other.Length) return false;
-
-    for (int i = 0; i < Length; i++) {
-      if (this[i] != other[i]) return false;
-    }
-
-    return true;
-  }
-
-  public int IndexOf(string lookingFor, int startOffset = 0) {
-    int result = Base.IndexOf(lookingFor, StartIndex + startOffset, StringComparison.Ordinal);
-    return result == -1 || result >= EndIndex ? -1 : result - StartIndex;
-  }
-
-  public int IndexOf(char lookingFor, int startOffset = 0) {
-    int result = Base.IndexOf(lookingFor, StartIndex + startOffset);
-    return result == -1 || result >= EndIndex ? -1 : result - StartIndex;
-  }
-
-  public Slice UnixLine(int count) {
-    if (count <= 0) throw new ArgumentException("Count must be greater than 0", nameof(count));
-
-    int lineStart = 0;
-    for (int i = 1; i < count; i++) {
-      lineStart = IndexOf('\n', lineStart);
-      if (lineStart < 0) throw new ArgumentException($"The string has only {i - 1} lines, not {count}");
-      lineStart++;
-    }
-
-    int lineEnd = IndexOf('\n', lineStart);
-    return lineEnd == -1 ? new Slice(Base, StartIndex + lineStart, EndIndex) : new Slice(Base, StartIndex + lineStart, StartIndex + lineEnd);
-  }
-
-  public override bool Equals(object obj) {
-    if (ReferenceEquals(this, obj)) return true;
-    if (obj is Slice other) return SameAs(other);
-    return false;
-  }
-
-  public override int GetHashCode() {
-    int h = 0;
-    for (int i = StartIndex; i < EndIndex; i++) {
-      h = 31 * h + Base[i];
-    }
-    return h;
-  }
-
-  public string ReplaceSelfWith(string s) {
-    int deltaLength = s.Length - Length;
-    var builder = new System.Text.StringBuilder(Base.Length + deltaLength);
-    builder.Append(Base, 0, StartIndex);
-    builder.Append(s);
-    builder.Append(Base, EndIndex, Base.Length - EndIndex);
-    return builder.ToString();
-  }
-
-  public int BaseLineAtOffset(int index) {
-    return 1 + new Slice(Base, 0, index).Count(c => c == '\n');
-  }
-
-  private int Count(Func<char, bool> predicate) {
-    int count = 0;
-    for (int i = StartIndex; i < EndIndex; i++) {
-      if (predicate(Base[i])) count++;
-    }
-    return count;
-  }
-}