C# Stack.PeekOrDefault方法代码示例

		static void ApplyToRange(ITextEditor editor, Stack<string> indentation, int begin, int end, int selBegin, int selEnd)
		{
			bool multiLine = false;
			
			for (int i = begin; i <= end; i++) {
				IDocumentLine curLine = editor.Document.GetLine(i);
				string lineText = curLine.Text.TrimStart(' ', '\t', '\r', '\n');
				string noComments = lineText.TrimComments().TrimEnd(' ', '\t', '\r', '\n');
				
				if (i < selBegin || i > selEnd) {
					indentation.PopOrDefault();
					indentation.Push(DocumentUtilitites.GetWhitespaceAfter(editor.Document, curLine.Offset));
				}
				
				// change indentation before (indent this line)
				if (multiLine && noComments.EndsWith("}", StringComparison.OrdinalIgnoreCase)) {
					Unindent(indentation);
					multiLine = false;
				}
				
				editor.Document.SmartReplaceLine(curLine, (indentation.PeekOrDefault() ?? string.Empty) + lineText);
				
				// change indentation afterwards (indent next line)
				if (!multiLine && noComments.EndsWith("_", StringComparison.OrdinalIgnoreCase)) {
					Indent(editor, indentation);
					multiLine = true;
				}

				if (multiLine && !noComments.EndsWith("_", StringComparison.OrdinalIgnoreCase)) {
					multiLine = false;
					Unindent(indentation);
				}
			}
		}

		static void Indent(ITextEditor editor, Stack<string> indentation)
		{
			indentation.Push((indentation.PeekOrDefault() ?? string.Empty) + editor.Options.IndentationString);
		}

		static void ApplyToRange(ITextEditor editor, Stack<string> indentation, List<int> eols, int blockStart, int blockEnd, int selectionStart, int selectionEnd, bool sawAttribute) {
			LoggingService.InfoFormatted("indenting line {0} to {1} with {2}", blockStart, blockEnd, (indentation.PeekOrDefault() ?? "").Length);
			
			int nextEol = -1;
			bool wasMultiLine = false;
			
			for (int i = blockStart; i <= blockEnd; i++) {
				IDocumentLine curLine = editor.Document.GetLine(i);
				string lineText = curLine.Text.TrimStart();
				// preprocessor directives cannot be multiline (just as comments)
				// and they are not included in normal block indentation ->
				// treat preprocessor directives as comments -> remove them
				string noComments = lineText.TrimComments().TrimPreprocessorDirectives().TrimEnd().TrimEnd('_').TrimEnd();
				
				// adjust indentation if the current line is not selected
				// lines between the selection will be aligned to the selected level
				if (i < selectionStart || i > selectionEnd) {
					indentation.PopOrDefault();
					indentation.Push(DocumentUtilitites.GetWhitespaceAfter(editor.Document, curLine.Offset));
				}
				
				// look for next eol if line is not empty
				// (the lexer does not produce eols for empty lines)
				if (!string.IsNullOrEmpty(noComments) && i >= nextEol) {
					int search = eols.BinarySearch(i);
					if (search < 0)
						search = ~search;
					nextEol = search < eols.Count ? eols[search] : i;
				}
				
				// remove indentation in last line of multiline array(, collection, object) initializers
				if (i == nextEol && wasMultiLine && (noComments == "}" || sawAttribute)) {
					wasMultiLine = false;
					Unindent(indentation);
				}
				
				// apply the indentation
				editor.Document.SmartReplaceLine(curLine, (indentation.PeekOrDefault() ?? "") + lineText);
				
				// indent line if it is ended by (implicit) line continuation
				if (i < nextEol && !wasMultiLine) {
					wasMultiLine = true;
					Indent(editor, indentation);
				}
				
				// unindent if this is the last line of a multiline statement
				if (i == nextEol && wasMultiLine) {
					wasMultiLine = false;
					Unindent(indentation);
				}
			}
		}

		static int SmartIndentInternal(ITextEditor editor, int begin, int end)
		{
			ILexer lexer = ParserFactory.CreateLexer(SupportedLanguage.VBNet, new StringReader(editor.Document.Text));
			
			Stack<string> indentation = new Stack<string>();
			
			indentation.Push(string.Empty);
			
			int oldLine = 1;
			
			bool inInterface = false;
			bool isMustOverride = false;
			bool isDeclare = false;
			bool isDelegate = false;
			
			Token currentToken = null;
			Token prevToken = null;
			
			while ((currentToken = lexer.NextToken()).Kind != Tokens.EOF) {
				if (prevToken == null)
					prevToken = currentToken;
				
				if (currentToken.Kind == Tokens.MustOverride)
					isMustOverride = true;
				
				if (currentToken.Kind == Tokens.Delegate)
					isDelegate = true;
				
				if (currentToken.Kind == Tokens.Declare)
					isDeclare = true;
				
				if (currentToken.Kind == Tokens.EOL)
					isDelegate = isDeclare = isMustOverride = false;
				
				if (IsBlockEnd(currentToken, prevToken)) {
					ApplyToRange(editor, indentation, oldLine, currentToken.Location.Line, begin, end);
					
					if (currentToken.Kind == Tokens.Interface)
						inInterface = false;
					
					if (!inInterface && !isMustOverride && !isDeclare && !isDelegate) {
						Unindent(indentation);
						
						if (currentToken.Kind == Tokens.Select)
							Unindent(indentation);
					}
					
					oldLine = currentToken.Location.Line;
				}
				
				if (IsBlockStart(lexer, currentToken, prevToken)) {
					int line = GetLastVisualLine(currentToken.Location.Line, editor);
					ApplyToRange(editor, indentation, oldLine, line, begin, end);
					
					if (!inInterface && !isMustOverride && !isDeclare && !isDelegate) {
						Indent(editor, indentation);
						
						if (currentToken.Kind == Tokens.Select)
							Indent(editor, indentation);
					}
					
					if (currentToken.Kind == Tokens.Interface)
						inInterface = true;
					
					oldLine = line + 1;
				}
				
				prevToken = currentToken;
			}
			
			// do last indent step
			int newLine = prevToken.Location.Line;
			
			if (oldLine > newLine)
				newLine = oldLine;
			
			ApplyToRange(editor, indentation, oldLine, newLine, begin, end);
			
			return (indentation.PeekOrDefault() ?? string.Empty).Length;
		}

//.........这里部分代码省略.........
			
			while ((currentToken = lexer.NextToken()).Kind != Tokens.EOF) {
				if (context.InContext(Context.Attribute) && currentToken.Kind == Tokens.GreaterThan)
					sawAttribute = true;
				
				context.InformToken(currentToken);
				
				if (prevToken == null)
					prevToken = currentToken;
				
				if (currentToken.Kind == Tokens.MustOverride)
					isMustOverride = true;
				
				if (currentToken.Kind == Tokens.Delegate)
					isDelegate = true;
				
				if (currentToken.Kind == Tokens.Declare)
					isDeclare = true;
				
				if (currentToken.Kind == Tokens.EOL) {
					isDelegate = isDeclare = isMustOverride = sawAttribute = false;
					eols.Add(currentToken.Location.Line);
				}
				
				if (IsBlockEnd(currentToken, prevToken)) {
					// indent the lines inside the block
					// this is an End-statement
					// hence we indent from blockStart to the previous line
					int blockEnd = currentToken.Location.Line - 1;
					
					// if this is a lambda end include End-Statement in block
//					if (lambdaNesting > 0 && (currentToken.Kind == Tokens.Function || currentToken.Kind == Tokens.Sub)) {
//						blockEnd++;
//					}
					
					ApplyToRange(editor, indentation, eols, blockStart, blockEnd, begin, end, sawAttribute);
					
					if (lambdaNesting > 0 && (currentToken.Kind == Tokens.Function || currentToken.Kind == Tokens.Sub)) {
						Unindent(indentation);
						
						ApplyToRange(editor, indentation, eols, currentToken.Location.Line, currentToken.Location.Line, begin, end, sawAttribute);
					}
					
					if (currentToken.Kind == Tokens.Interface)
						inInterface = false;
					
					if (!inInterface && !isMustOverride && !isDeclare && !isDelegate) {
						Unindent(indentation);
						
						if (currentToken.Kind == Tokens.Select)
							Unindent(indentation);
					}
					
					// block start is this line (for the lines between two blocks)
					blockStart = currentToken.Location.Line;
					
					if (lambdaNesting > 0 && (currentToken.Kind == Tokens.Function || currentToken.Kind == Tokens.Sub)) {
						blockStart++;
						lambdaNesting--;
					}
				}
				
				bool isMultiLineLambda;
				if (IsBlockStart(lexer, currentToken, prevToken, out isMultiLineLambda)) {
					// indent the lines between the last and this block
					// this is a Begin-statement
					// hence we indent from blockStart to the this line
					int lastVisualLine = FindNextEol(lexer);
					eols.Add(lastVisualLine);
					ApplyToRange(editor, indentation, eols, blockStart, lastVisualLine, begin, end, sawAttribute);
					
					if (isMultiLineLambda && (currentToken.Kind == Tokens.Function || currentToken.Kind == Tokens.Sub)) {
						lambdaNesting++;
						int endColumn = currentToken.Location.Column;
						int startColumn = DocumentUtilitites.GetWhitespaceAfter(editor.Document, editor.Document.GetLine(lastVisualLine).Offset).Length;
						if (startColumn < endColumn)
							Indent(editor, indentation, new string(' ', endColumn - startColumn - 1));
					}
					
					if (!inInterface && !isMustOverride && !isDeclare && !isDelegate && !IsAutomaticPropertyWithDefaultValue(lexer, currentToken, prevToken)) {
						Indent(editor, indentation);
						
						if (currentToken.Kind == Tokens.Select)
							Indent(editor, indentation);
					}
					
					if (currentToken.Kind == Tokens.Interface)
						inInterface = true;
					
					// block start is the following line (for the lines inside a block)
					blockStart = lastVisualLine + 1;
				}
				
				prevToken = currentToken;
			}
			
			ApplyToRange(editor, indentation, eols, blockStart, editor.Document.TotalNumberOfLines, begin, end, sawAttribute);
			
			return (indentation.PeekOrDefault() ?? string.Empty).Length;
		}