From d4619878398a2935ca56d089dbef4ae89b755859 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Mike=20Kr=C3=BCger?= <mkrueger@xamarin.com>
Date: Wed, 2 Nov 2011 08:06:47 +0100
Subject: [PATCH] Improved comment & string context recognition.

---
 .../Completion/CSharpCompletionEngine.cs      | 12 +--
 .../Completion/CSharpCompletionEngineBase.cs  | 90 +++++++++++++++++--
 .../CSharpParameterCompletionEngine.cs        |  2 +-
 3 files changed, 88 insertions(+), 16 deletions(-)

diff --git a/ICSharpCode.NRefactory.CSharp/Completion/CSharpCompletionEngine.cs b/ICSharpCode.NRefactory.CSharp/Completion/CSharpCompletionEngine.cs
index bb439b8c16..21479c399c 100644
--- a/ICSharpCode.NRefactory.CSharp/Completion/CSharpCompletionEngine.cs
+++ b/ICSharpCode.NRefactory.CSharp/Completion/CSharpCompletionEngine.cs
@@ -150,7 +150,7 @@ namespace ICSharpCode.NRefactory.CSharp.Completion
 			// Magic key completion
 			case ':':
 			case '.':
-				if (IsInsideComment () || IsInsideString ())
+				if (IsInsideCommentOrString ())
 					return Enumerable.Empty<ICompletionData> ();
 				var expr = GetExpressionBeforeCursor ();
 				if (expr == null)
@@ -172,7 +172,7 @@ namespace ICSharpCode.NRefactory.CSharp.Completion
 				
 				return CreateCompletionData (location, resolveResult.Item1, expr.Item2, resolveResult.Item2);
 			case '#':
-				if (IsInsideComment () || IsInsideString ())
+				if (IsInsideCommentOrString ())
 					return null;
 				return GetDirectiveCompletionData ();
 			
@@ -210,7 +210,7 @@ namespace ICSharpCode.NRefactory.CSharp.Completion
 			
 			// Parameter completion
 			case '(':
-				if (IsInsideComment () || IsInsideString ())
+				if (IsInsideCommentOrString ())
 					return null;
 				var invoke = GetInvocationBeforeCursor (true);
 				if (invoke == null)
@@ -237,7 +237,7 @@ namespace ICSharpCode.NRefactory.CSharp.Completion
 				
 			// Completion on space:
 			case ' ':
-				if (IsInsideComment () || IsInsideString ())
+				if (IsInsideCommentOrString ())
 					return null;
 				
 				int tokenIndex = offset;
@@ -395,7 +395,7 @@ namespace ICSharpCode.NRefactory.CSharp.Completion
 				return keywordCompletion;
 			// Automatic completion
 			default:
-				if (IsInsideComment () || IsInsideString ())
+				if (IsInsideCommentOrString ())
 					return null;
 				if (IsInLinqContext (offset)) {
 					tokenIndex = offset;
@@ -741,7 +741,7 @@ namespace ICSharpCode.NRefactory.CSharp.Completion
 		
 		IEnumerable<ICompletionData> HandleKeywordCompletion (int wordStart, string word)
 		{
-			if (IsInsideComment () || IsInsideString ())
+			if (IsInsideCommentOrString ())
 				return null;
 			switch (word) {
 			case "using":
diff --git a/ICSharpCode.NRefactory.CSharp/Completion/CSharpCompletionEngineBase.cs b/ICSharpCode.NRefactory.CSharp/Completion/CSharpCompletionEngineBase.cs
index cfc619a87e..767826ba8a 100644
--- a/ICSharpCode.NRefactory.CSharp/Completion/CSharpCompletionEngineBase.cs
+++ b/ICSharpCode.NRefactory.CSharp/Completion/CSharpCompletionEngineBase.cs
@@ -57,6 +57,8 @@ namespace ICSharpCode.NRefactory.CSharp.Completion
 		
 		protected void SetOffset (int offset)
 		{
+			Reset ();
+			
 			this.offset = offset;
 			this.location = document.GetLocation (offset);
 			
@@ -65,9 +67,74 @@ namespace ICSharpCode.NRefactory.CSharp.Completion
 		}
 		
 		#region Context helper methods
-		protected bool IsInsideComment ()
+		protected bool IsInsideCommentOrString ()
 		{
-			return IsInsideComment (offset);
+			var text = GetMemberTextToCaret ();
+			bool inSingleComment = false, inString = false, inVerbatimString = false, inChar = false, inMultiLineComment = false;
+			
+			for (int i = 0; i < text.Item1.Length - 1; i++) {
+				char ch = text.Item1[i];
+				char nextCh = text.Item1[i + 1];
+				
+				switch (ch) {
+				case '/':
+					if (inString || inChar || inVerbatimString)
+						break;
+					if (nextCh == '/') {
+						i++;
+						inSingleComment = true;
+					}
+					if (nextCh == '*')
+						inMultiLineComment = true;
+					break;
+				case '*':
+					if (inString || inChar || inVerbatimString || inSingleComment)
+						break;
+					if (nextCh == '/') {
+						i++;
+						inMultiLineComment = false;
+					}
+					break;
+				case '@':
+					if (inString || inChar || inVerbatimString || inSingleComment || inMultiLineComment)
+						break;
+					if (nextCh == '"') {
+						i++;
+						inVerbatimString = true;
+					}
+					break;
+				case '\n':
+				case '\r':
+					inSingleComment = false;
+					inString = false;
+					inChar = false;
+					break;
+				case '\\':
+					if (inString || inChar)
+						i++;
+					break;
+				case '"':
+					if (inSingleComment || inMultiLineComment || inChar)
+						break;
+					if (inVerbatimString) {
+						if (nextCh == '"') {
+							i++;
+							break;
+						}
+						inVerbatimString = false;
+						break;
+					}
+					inString = !inString;
+					break;
+				case '\'':
+					if (inSingleComment || inMultiLineComment || inString || inVerbatimString)
+						break;
+					inChar = !inChar;
+					break;
+				}
+			}
+			
+			return inSingleComment || inString || inVerbatimString || inChar || inMultiLineComment;
 		}
 		
 		protected bool IsInsideComment (int offset)
@@ -83,11 +150,6 @@ namespace ICSharpCode.NRefactory.CSharp.Completion
 			return cmt != null && cmt.CommentType == CommentType.Documentation;
 		}
 		
-		protected bool IsInsideString ()
-		{
-			return IsInsideString (offset);
-		}
-		
 		protected bool IsInsideString (int offset)
 		{
 			
@@ -240,6 +302,13 @@ namespace ICSharpCode.NRefactory.CSharp.Completion
 			}
 		}
 		
+		string cachedText = null;
+		
+		protected virtual void Reset ()
+		{
+			cachedText = null;
+		}
+		
 		protected Tuple<string, bool> GetMemberTextToCaret ()
 		{
 			int startOffset;
@@ -250,9 +319,12 @@ namespace ICSharpCode.NRefactory.CSharp.Completion
 			} else {
 				startOffset = 0;
 			}
-			return Tuple.Create (document.GetText (startOffset, offset - startOffset), startOffset != 0);
+			if (cachedText == null)
+				cachedText = document.GetText (startOffset, offset - startOffset);
+			
+			return Tuple.Create (cachedText, startOffset != 0);
 		}
-
+		
 		protected Tuple<CSharpParsedFile, AstNode, CompilationUnit> GetInvocationBeforeCursor (bool afterBracket)
 		{
 			CompilationUnit baseUnit;
diff --git a/ICSharpCode.NRefactory.CSharp/Completion/CSharpParameterCompletionEngine.cs b/ICSharpCode.NRefactory.CSharp/Completion/CSharpParameterCompletionEngine.cs
index 634d758e73..6aaa6716ea 100644
--- a/ICSharpCode.NRefactory.CSharp/Completion/CSharpParameterCompletionEngine.cs
+++ b/ICSharpCode.NRefactory.CSharp/Completion/CSharpParameterCompletionEngine.cs
@@ -77,7 +77,7 @@ namespace ICSharpCode.NRefactory.CSharp.Completion
 			char completionChar = document.GetCharAt (offset - 1);
 			if (completionChar != '(' && completionChar != '<' && completionChar != '[')
 				return null;
-			if (IsInsideComment () || IsInsideString ())
+			if (IsInsideCommentOrString ())
 				return null;
 			
 			var invoke = GetInvocationBeforeCursor (true) ?? GetIndexerBeforeCursor ();