initial commit

Mono.Assembler/ILReader.cs

@@ -0,0 +1,164 @@
+// ILReader.cs
+// Author: Sergey Chaban ([email protected])
+
+using System;
+using System.IO;
+using System.Text;
+using System.Collections;
+
+namespace Mono.Assembler
+{
+	/// <summary>
+	/// </summary>
+	public class ILReader
+	{
+		private StreamReader reader;
+		private Stack putback_stack;
+		private Location location;
+		private Location markedLocation;
+
+		public ILReader(StreamReader reader)
+		{
+			this.reader = reader;
+			putback_stack = new Stack();
+
+			location = new Location();
+			markedLocation = Location.Unknown;
+		}
+
+
+		/// <summary>
+		/// </summary>
+		public Location Location
+		{
+			get { return location; }
+		}
+
+
+		/// <summary>
+		/// Provides access to underlying StreamReader.
+		/// </summary>
+		public StreamReader BaseReader
+		{
+			get { return reader; }
+		}
+
+		private int DoRead()
+		{
+			if (putback_stack.Count > 0)
+				return (char) putback_stack.Pop();
+
+			return reader.Read();
+		}
+
+		private int DoPeek()
+		{
+			if (putback_stack.Count > 0)
+				return (char) putback_stack.Peek();
+
+			return reader.Peek();
+		}
+
+		/// <summary>
+		/// </summary>
+		/// <returns></returns>
+		public int Read()
+		{
+			int read = DoRead();
+			if (read == '\n')
+				location.NewLine();
+			else
+				location.NextColumn();
+			return read;
+		}
+
+		/// <summary>
+		/// </summary>
+		/// <returns></returns>
+		public int Peek()
+		{
+			return DoPeek();
+		}
+
+
+		/// <summary>
+		/// </summary>
+		public void Unread(char c)
+		{
+			putback_stack.Push(c);
+
+			if ('\n' == c)
+				location.PreviousLine();
+
+			location.PreviousColumn();
+		}
+
+
+		/// <summary>
+		/// </summary>
+		/// <param name="chars"></param>
+		public void Unread(char[] chars)
+		{
+			for (int i = chars.Length - 1; i >= 0; i--)
+				Unread(chars[i]);
+		}
+
+		/// <summary>
+		/// </summary>
+		/// <param name="c"></param>
+		public void Unread(int c)
+		{
+			Unread((char) c);
+		}
+
+
+		/// <summary>
+		/// </summary>
+		public void SkipWhitespace()
+		{
+			int ch = Read();
+			for (; ch != -1 && Char.IsWhiteSpace((char) ch); ch = Read()) ;
+			if (ch != -1) Unread(ch);
+		}
+
+
+		/// <summary>
+		/// </summary>
+		/// <returns></returns>
+		public string ReadToWhitespace()
+		{
+			StringBuilder sb = new StringBuilder();
+			int ch = Read();
+			for (; ch != -1 && !Char.IsWhiteSpace((char) ch); sb.Append((char) ch), ch = Read()) ;
+			if (ch != -1) Unread(ch);
+			return sb.ToString();
+		}
+
+
+		/// <summary>
+		/// </summary>
+		public void MarkLocation()
+		{
+			if (markedLocation == Location.Unknown)
+			{
+				markedLocation = new Location(location);
+			}
+			else
+			{
+				markedLocation.CopyFrom(location);
+			}
+		}
+
+
+		/// <summary>
+		/// </summary>
+		public void RestoreLocation()
+		{
+			if (markedLocation != Location.Unknown)
+			{
+				location.CopyFrom(markedLocation);
+			}
+		}
+	}
+}
+