implemented state handling in ILexer and AbstractLexer to make it publicly available

git-svn-id: svn://svn.sharpdevelop.net/sharpdevelop/branches/vbnet@6084 1ccf3a8d-04fe-1044-b7c0-cef0b8235c61

src/Libraries/NRefactory/Project/NRefactory.csproj

@@ -61,6 +61,7 @@
   </ItemGroup>
   <ItemGroup>
     <Compile Include="Src\Lexer\LATextReader.cs" />
+    <Compile Include="Src\Lexer\AbstractLexerState.cs" />
     <Compile Include="Src\Lexer\VBNet\ExpressionFinder.cs" />
     <Compile Include="Src\Lexer\VBNet\Parser.cs">
       <DependentUpon>ExpressionFinder.atg</DependentUpon>
@@ -90,6 +91,8 @@
     <Compile Include="..\..\..\Main\GlobalAssemblyInfo.cs">
       <Link>Configuration\GlobalAssemblyInfo.cs</Link>
     </Compile>
+    <Compile Include="Src\Lexer\VBNet\VBLexerState.cs" />
+    <Compile Include="Src\Lexer\VBNet\XmlModeInfo.cs" />
     <Compile Include="Src\OperatorPrecedence.cs" />
     <Compile Include="Src\Parser\CSharp\CSharpParser.cs" />
     <Compile Include="Src\Parser\CSharp\Parser.cs" />

src/Libraries/NRefactory/Project/Src/Lexer/AbstractLexer.cs

@@ -196,6 +196,13 @@ namespace ICSharpCode.NRefactory.Parser
 			this.reader = new LATextReader(reader);
 		}
 		
+		protected AbstractLexer(TextReader reader, AbstractLexerState state)
+			: this(reader)
+		{
+			SetInitialLocation(new Location(state.Column, state.Line));
+			lastToken = new Token(state.PrevTokenKind, 0, 0);
+		}
+		
 		#region System.IDisposable interface implementation
 		public virtual void Dispose()
 		{
@@ -360,5 +367,19 @@ namespace ICSharpCode.NRefactory.Parser
 		/// After the call, Lexer.LookAhead will be the block-closing token.
 		/// </summary>
 		public abstract void SkipCurrentBlock(int targetToken);
+		
+		public event EventHandler SavepointReached;
+		
+		protected virtual void OnSavepointReached(EventArgs e)
+		{
+			if (SavepointReached != null) {
+				SavepointReached(this, e);
+			}
+		}
+		
+		public virtual AbstractLexerState Export()
+		{
+			throw new NotSupportedException();
+		}
 	}
 }

src/Libraries/NRefactory/Project/Src/Lexer/AbstractLexerState.cs

@@ -0,0 +1,17 @@
+// <file>
+//     <copyright see="prj:///doc/copyright.txt"/>
+//     <license see="prj:///doc/license.txt"/>
+//     <owner name="Siegfried Pammer" email="siegfriedpammer@gmail.com" />
+//     <version>$Revision$</version>
+// </file>
+using System;
+
+namespace ICSharpCode.NRefactory.Parser
+{
+	public abstract class AbstractLexerState
+	{
+		public int Line { get; set; }
+		public int Column { get; set; }
+		public int PrevTokenKind { get; set; }
+	}
+}

src/Libraries/NRefactory/Project/Src/Lexer/ILexer.cs

@@ -106,5 +106,17 @@ namespace ICSharpCode.NRefactory.Parser
 		/// After the call, Lexer.LookAhead will be the block-closing token.
 		/// </summary>
 		void SkipCurrentBlock(int targetToken);
+		
+		/// <summary>
+		/// Used to export the current state of the lexer. The exported state should be
+		/// complete, so that it is possible to reset the lexer to a previous state completely.
+		/// </summary>
+		AbstractLexerState Export();
+		
+		/// <summary>
+		/// Is fired by the lexer as soon as a savepoint is reached.
+		/// The Export-method can be used to retrieve the current state.
+		/// </summary>
+		event EventHandler SavepointReached;
 	}
 }

src/Libraries/NRefactory/Project/Src/Lexer/VBNet/Lexer.cs

@@ -34,17 +34,19 @@ namespace ICSharpCode.NRefactory.Parser.VB
 			ef = new ExpressionFinder();
 		}
 		
-		public Lexer(TextReader reader, LexerState state) : base(reader)
+		public Lexer(TextReader reader, AbstractLexerState state) : base(reader, state)
 		{
-			ef = new ExpressionFinder(state.ExpressionFinder);
-			SetInitialLocation(new Location(state.Column, state.Line));
-			lineEnd = state.LineEnd;
-			isAtLineBegin = state.IsAtLineBegin;
-			lastToken = new Token(state.PrevTokenKind, 0, 0);
-			encounteredLineContinuation = state.EncounteredLineContinuation;
-			misreadExclamationMarkAsTypeCharacter = state.MisreadExclamationMarkAsTypeCharacter;
-			xmlModeStack = new Stack<XmlModeInfo>(state.XmlModeInfoStack.Select(i => (XmlModeInfo)i.Clone()).Reverse());
-			inXmlMode = state.InXmlMode;
+			if (!(state is VBLexerState))
+				throw new InvalidOperationException("state must be a VBLexerState");
+			
+			var vbState = state as VBLexerState;
+			ef = new ExpressionFinder(vbState.ExpressionFinder);
+			lineEnd = vbState.LineEnd;
+			isAtLineBegin = vbState.IsAtLineBegin;
+			encounteredLineContinuation = vbState.EncounteredLineContinuation;
+			misreadExclamationMarkAsTypeCharacter = vbState.MisreadExclamationMarkAsTypeCharacter;
+			xmlModeStack = new Stack<XmlModeInfo>(vbState.XmlModeInfoStack.Select(i => (XmlModeInfo)i.Clone()).Reverse());
+			inXmlMode = vbState.InXmlMode;
 		}
 		
 		Token NextInternal()
@@ -1131,9 +1133,9 @@ namespace ICSharpCode.NRefactory.Parser.VB
 			ef.SetContext(type);
 		}
 		
-		public LexerState Export()
+		public override AbstractLexerState Export()
 		{
-			return new LexerState() {
+			return new VBLexerState() {
 				Column = Col,
 				Line = Line,
 				EncounteredLineContinuation = encounteredLineContinuation,
@@ -1147,40 +1149,4 @@ namespace ICSharpCode.NRefactory.Parser.VB
 			};
 		}
 	}
-	
-	public class XmlModeInfo : ICloneable
-	{
-		public bool inXmlTag, inXmlCloseTag, isDocumentStart;
-		public int level;
-		
-		public XmlModeInfo(bool isSpecial)
-		{
-			level = isSpecial ? -1 : 0;
-			inXmlTag = inXmlCloseTag = isDocumentStart = false;
-		}
-		
-		public object Clone()
-		{
-			return new XmlModeInfo(false) {
-				inXmlCloseTag = this.inXmlCloseTag,
-				inXmlTag = this.inXmlTag,
-				isDocumentStart = this.isDocumentStart,
-				level = this.level
-			};
-		}
-	}
-	
-	public class LexerState
-	{
-		public bool LineEnd { get; set; }
-		public bool IsAtLineBegin { get; set; }
-		public bool MisreadExclamationMarkAsTypeCharacter { get; set; }
-		public bool EncounteredLineContinuation { get; set; }
-		public ExpressionFinderState ExpressionFinder { get; set; }
-		public Stack<XmlModeInfo> XmlModeInfoStack { get; set; }
-		public bool InXmlMode { get; set; }
-		public int Line { get; set; }
-		public int Column { get; set; }
-		public int PrevTokenKind { get; set; }
-	}
 }

src/Libraries/NRefactory/Project/Src/Lexer/VBNet/VBLexerState.cs

@@ -0,0 +1,23 @@
+// <file>
+//     <copyright see="prj:///doc/copyright.txt"/>
+//     <license see="prj:///doc/license.txt"/>
+//     <owner name="Siegfried Pammer" email="siegfriedpammer@gmail.com" />
+//     <version>$Revision: 6083 $</version>
+// </file>
+
+using System;
+using System.Collections.Generic;
+
+namespace ICSharpCode.NRefactory.Parser.VB
+{
+	public sealed class VBLexerState : AbstractLexerState
+	{
+		public bool LineEnd { get; set; }
+		public bool IsAtLineBegin { get; set; }
+		public bool MisreadExclamationMarkAsTypeCharacter { get; set; }
+		public bool EncounteredLineContinuation { get; set; }
+		public ExpressionFinderState ExpressionFinder { get; set; }
+		public Stack<XmlModeInfo> XmlModeInfoStack { get; set; }
+		public bool InXmlMode { get; set; }
+	}
+}

src/Libraries/NRefactory/Project/Src/Lexer/VBNet/XmlModeInfo.cs

@@ -0,0 +1,33 @@
+// <file>
+//     <copyright see="prj:///doc/copyright.txt"/>
+//     <license see="prj:///doc/license.txt"/>
+//     <owner name="Siegfried Pammer" email="siegfriedpammer@gmail.com" />
+//     <version>$Revision: 6083 $</version>
+// </file>
+
+using System;
+
+namespace ICSharpCode.NRefactory.Parser.VB
+{
+	public class XmlModeInfo : ICloneable
+	{
+		public bool inXmlTag, inXmlCloseTag, isDocumentStart;
+		public int level;
+		
+		public XmlModeInfo(bool isSpecial)
+		{
+			level = isSpecial ? -1 : 0;
+			inXmlTag = inXmlCloseTag = isDocumentStart = false;
+		}
+		
+		public object Clone()
+		{
+			return new XmlModeInfo(false) {
+				inXmlCloseTag = this.inXmlCloseTag,
+				inXmlTag = this.inXmlTag,
+				isDocumentStart = this.isDocumentStart,
+				level = this.level
+			};
+		}
+	}
+}

src/Libraries/NRefactory/Project/Src/ParserFactory.cs

@@ -8,6 +8,7 @@
 using System;
 using System.IO;
 using System.Text;
+using ICSharpCode.NRefactory.Parser;
 
 namespace ICSharpCode.NRefactory
 {
@@ -32,6 +33,18 @@ namespace ICSharpCode.NRefactory
 			throw new System.NotSupportedException(language + " not supported.");
 		}
 		
+		public static Parser.ILexer CreateLexer(SupportedLanguage language, TextReader textReader, AbstractLexerState state)
+		{
+			switch (language) {
+				case SupportedLanguage.CSharp:
+					//return new ICSharpCode.NRefactory.Parser.CSharp.Lexer(textReader, state);
+					throw new System.NotSupportedException("C# Lexer does not support loading a previous state.");
+				case SupportedLanguage.VBNet:
+					return new ICSharpCode.NRefactory.Parser.VB.Lexer(textReader, state);
+			}
+			throw new System.NotSupportedException(language + " not supported.");
+		}
+		
 		public static IParser CreateParser(SupportedLanguage language, TextReader textReader)
 		{
 			Parser.ILexer lexer = CreateLexer(language, textReader);