1 files changed, 166 insertions, 0 deletions
diff --git a/mcs/ilasm/scanner/ILReader.cs b/mcs/ilasm/scanner/ILReader.cs
new file mode 100644
index 00000000000..72de8861b43
--- /dev/null
+++ b/mcs/ilasm/scanner/ILReader.cs
@@ -0,0 +1,166 @@
+// ILReader.cs
+// Author: Sergey Chaban (serge@wildwestsoftware.com)
+
+using System;
+using System.IO;
+using System.Text;
+using System.Collections;
+
+namespace Mono.ILASM {
+
+
+	/// <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);
+			}
+		}
+
+	}
+
+}
+