Reorganizes Project (#41)

Projects/Scripts/Commands/Generic/Extensions/DistinctExtension.cs

@@ -0,0 +1,84 @@
+using System;
+using System.Collections.Generic;
+
+namespace Server.Commands.Generic
+{
+  public sealed class DistinctExtension : BaseExtension
+  {
+    public static ExtensionInfo ExtInfo =
+      new ExtensionInfo(30, "Distinct", -1, () => new DistinctExtension());
+
+    private IComparer<object> m_Comparer;
+
+    private List<Property> m_Properties;
+
+    public DistinctExtension()
+    {
+      m_Properties = new List<Property>();
+    }
+
+    public override ExtensionInfo Info => ExtInfo;
+
+    public static void Initialize()
+    {
+      ExtensionInfo.Register(ExtInfo);
+    }
+
+    public override void Optimize(Mobile from, Type baseType, ref AssemblyEmitter assembly)
+    {
+      if (baseType == null)
+        throw new Exception("Distinct extension may only be used in combination with an object conditional.");
+
+      foreach (Property prop in m_Properties)
+      {
+        prop.BindTo(baseType, PropertyAccess.Read);
+        prop.CheckAccess(from);
+      }
+
+      if (assembly == null)
+        assembly = new AssemblyEmitter("__dynamic");
+
+      m_Comparer = DistinctCompiler.Compile<object>(assembly, baseType, m_Properties.ToArray());
+    }
+
+    public override void Parse(Mobile from, string[] arguments, int offset, int size)
+    {
+      if (size < 1)
+        throw new Exception("Invalid distinction syntax.");
+
+      int end = offset + size;
+
+      while (offset < end)
+      {
+        string binding = arguments[offset++];
+
+        m_Properties.Add(new Property(binding));
+      }
+    }
+
+    public override void Filter(List<object> list)
+    {
+      if (m_Comparer == null)
+        throw new InvalidOperationException("The extension must first be optimized.");
+
+      List<object> copy = new List<object>(list);
+
+      copy.Sort(m_Comparer);
+
+      list.Clear();
+
+      object last = null;
+
+      for (int i = 0; i < copy.Count; ++i)
+      {
+        object obj = copy[i];
+
+        if (last == null || m_Comparer.Compare(obj, last) != 0)
+        {
+          list.Add(obj);
+          last = obj;
+        }
+      }
+    }
+  }
+}