A Command Line Calculator

using System;
using System.Collections;
using System.Runtime.Serialization;
using System.Diagnostics;
using System.IO;
using System.Runtime.Serialization.Formatters.Binary;
namespace Calculate
{
	/// <summary>
	/// Summary description for Variables.
	/// </summary>
	[Serializable()]
	public class Variables:ICollection,ISerializable
	{
		#region Private Members
		private SortedList list;
		private static Variables variables;
		#endregion
		
		#region Constructors
		public Variables()
		{
			//
			// TODO: Add constructor logic here
			//
			list=new SortedList();
		}
		public Variables(SerializationInfo info, StreamingContext ctxt)
		{
			list=(SortedList)info.GetValue("list", typeof(SortedList));
			
		}
		#endregion

		#region ICollection Members

		public bool IsSynchronized
		{
			get
			{
				// TODO:  Add Variables.IsSynchronized getter implementation
				return false;
			}
		}

		public int Count
		{
			get
			{
				// TODO:  Add Variables.Count getter implementation
				return list.Count;
			}
		}

		public void CopyTo(Array array, int index)
		{
			// TODO:  Add Variables.CopyTo implementation
			list.CopyTo(array,index);
		}

		public object SyncRoot
		{
			get
			{
				// TODO:  Add Variables.SyncRoot getter implementation
				return list.SyncRoot;
			}
		}

		#endregion

		#region IEnumerable Members

		public IEnumerator GetEnumerator()
		{
			// TODO:  Add Variables.GetEnumerator implementation
			return list.GetEnumerator();
		}

		#endregion

		#region ISerializable Members

		public void GetObjectData(SerializationInfo info, StreamingContext context)
		{
			// TODO:  Add Variables.GetObjectData implementation
			info.AddValue("list", list);
		}
		#endregion

		#region Indexers
		public virtual double this[int Index]
		{
			get
			{
				return (double)list.GetByIndex(Index);
			}
		}
		public virtual double this[string key]
		{
			get
			{
				return (double)list[key];
			}
			set
			{
				if(list[key]==null)
				{
					list.Add(key,value);
				}
				else
				{
					list[key]=value;
				}
			}
		}
		#endregion

		#region Public Methods
		public void Add(string key,double value)
		{
			this[key]=value;
		}
		public void Clear()
		{
			list.Clear();
		}
		public string [] GetKeys()
		{
			string []keys=new string[list.Keys.Count];
			IList lst=list.GetKeyList();
			for(int i=0;i<keys.Length;i++)
			{
				keys[i]=(string)lst[i];
			}
			return keys;
		}
		#region Static Methods
		public static Variables GetVariables()
		{
			if(variables==null)
			{
				variables=new Variables();
			}
			return variables;
		}
		public static void Save()
		{
			Process p=Process.GetCurrentProcess();
			string path=System.IO.Path.GetDirectoryName(p.MainModule.FileName);
			FileStream stream=File.Create(path+@"\variables.dat");
			BinaryFormatter bformatter = new BinaryFormatter();
			bformatter.Serialize(stream, variables);
			stream.Close();
		}
		public static void Load()
		{
			try
			{
				Process p=Process.GetCurrentProcess();
				string path=System.IO.Path.GetDirectoryName(p.MainModule.FileName);
				FileStream stream=File.OpenRead(path+@"\variables.dat");
				BinaryFormatter bformatter = new BinaryFormatter();
				variables = (Variables)bformatter.Deserialize(stream);
				stream.Close();
			}
			catch
			{
				
			}
		}
		#endregion
		#endregion

		
	}
}