C# ForStatement类代码示例

 public override void VisitForStatement(ForStatement forStatement)
 {
     if (findReturn)
     {
         base.VisitForStatement(forStatement);
     }
 }

		public void Run (RefactoringContext context)
		{
			var foreachStatement = GetForeachStatement (context);
			
			var result = context.ResolveType (foreachStatement.InExpression);
			var countProperty = GetCountProperty (result);
			
			var initializer = new VariableDeclarationStatement (new PrimitiveType ("int"), "i", new PrimitiveExpression (0));
			var id1 = new IdentifierExpression ("i");
			var id2 = id1.Clone ();
			var id3 = id1.Clone ();
			
			var forStatement = new ForStatement () {
				Initializers = { initializer },
				Condition = new BinaryOperatorExpression (id1, BinaryOperatorType.LessThan, new MemberReferenceExpression (foreachStatement.InExpression.Clone (), countProperty)),
				Iterators = { new ExpressionStatement (new UnaryOperatorExpression (UnaryOperatorType.PostIncrement, id2)) },
				EmbeddedStatement = new BlockStatement {
					new VariableDeclarationStatement (foreachStatement.VariableType.Clone (), foreachStatement.VariableName, new IndexerExpression (foreachStatement.InExpression.Clone (), id3))
				}
			};
			
			if (foreachStatement.EmbeddedStatement is BlockStatement) {
				foreach (var child in ((BlockStatement)foreachStatement.EmbeddedStatement).Statements) {
					forStatement.EmbeddedStatement.AddChild (child.Clone (), BlockStatement.StatementRole);
				}
			} else {
				forStatement.EmbeddedStatement.AddChild (foreachStatement.EmbeddedStatement.Clone (), BlockStatement.StatementRole);
			}
			
			using (var script = context.StartScript ()) {
				script.Replace (foreachStatement, forStatement);
				script.Link (initializer.Variables.First ().NameToken, id1, id2, id3);
			}
		}

        public override void VisitForStatement(ForStatement node)
        {
            VisitChildren(node);

            // Special-case constant conditions
            var constant = BoolConstant(node.Condition);
            if (constant == true) {
                node.Condition.Remove();
            }

            ReplaceBlockWithSingleStatement(node.EmbeddedStatement);
        }

			public override void VisitForStatement (ForStatement forStatement)
			{
				base.VisitForStatement (forStatement);

				if (forStatement.Initializers.Count != 1)
					return;
				var variableDecl = forStatement.Initializers.First () as VariableDeclarationStatement;
				if (variableDecl == null)
					return;

				VariableInitializer controlVariable = null;
				if (forStatement.Condition is BinaryOperatorExpression) {
					controlVariable = GetControlVariable (variableDecl, (BinaryOperatorExpression)forStatement.Condition);
				} else if (forStatement.Condition is UnaryOperatorExpression) {
					controlVariable = GetControlVariable (variableDecl, (UnaryOperatorExpression)forStatement.Condition);
				} else if (forStatement.Condition is IdentifierExpression) {
					controlVariable = variableDecl.Variables.FirstOrDefault (
						v => v.Name == ((IdentifierExpression)forStatement.Condition).Identifier);
				}

				if (controlVariable == null)
					return;

				var localResolveResult = ctx.Resolve (controlVariable) as LocalResolveResult;
				if (localResolveResult == null)
					return;

				var results = ctx.FindReferences (forStatement, localResolveResult.Variable);
				var modified = false;
				foreach (var result in results) {
					if (modified)
						break;
					var node = result.Node;
					var unary = node.Parent as UnaryOperatorExpression;
					if (unary != null && unary.Expression == node) {
						modified = unary.Operator == UnaryOperatorType.Decrement ||
							unary.Operator == UnaryOperatorType.PostDecrement ||
							unary.Operator == UnaryOperatorType.Increment ||
							unary.Operator == UnaryOperatorType.PostIncrement;
						continue;
					}

					var assignment = node.Parent as AssignmentExpression;
					modified = assignment != null && assignment.Left == node;
				}

				if (!modified)
					AddIssue (controlVariable.NameToken,
						ctx.TranslateString ("'for' loop control variable is never modified"));

			}

		public IEnumerable<CodeAction> GetActions(RefactoringContext context)
		{
			var foreachStatement = GetForeachStatement(context);
			if (foreachStatement == null) {
				yield break;
			}
			yield return new CodeAction(context.TranslateString("Convert 'foreach' loop to 'for'"), script => {
				var result = context.Resolve(foreachStatement.InExpression);
				var countProperty = GetCountProperty(result.Type);
				
				// TODO: use another variable name if 'i' is already in use
				var initializer = new VariableDeclarationStatement(new PrimitiveType("int"), "i", new PrimitiveExpression(0));
				var id1 = new IdentifierExpression("i");
				var id2 = id1.Clone();
				var id3 = id1.Clone();
				
				var variableDeclarationStatement = new VariableDeclarationStatement(
					foreachStatement.VariableType.Clone(),
					foreachStatement.VariableName,
					new IndexerExpression(foreachStatement.InExpression.Clone(), id3)
				);
				var forStatement = new ForStatement() {
					Initializers = { initializer },
					Condition = new BinaryOperatorExpression (id1, BinaryOperatorType.LessThan, new MemberReferenceExpression (foreachStatement.InExpression.Clone (), countProperty)),
					Iterators = { new ExpressionStatement (new UnaryOperatorExpression (UnaryOperatorType.PostIncrement, id2)) },
					EmbeddedStatement = new BlockStatement {
						variableDeclarationStatement
					}
				};
				
				if (foreachStatement.EmbeddedStatement is BlockStatement) {
					variableDeclarationStatement.Remove();
					var oldBlock = (BlockStatement)foreachStatement.EmbeddedStatement.Clone();
					if (oldBlock.Statements.Any()) {
						oldBlock.Statements.InsertBefore(oldBlock.Statements.First(), variableDeclarationStatement);
					} else {
						oldBlock.Statements.Add(variableDeclarationStatement);
					}
					forStatement.EmbeddedStatement = oldBlock;
				} else {
					forStatement.EmbeddedStatement.AddChild (foreachStatement.EmbeddedStatement.Clone (), BlockStatement.StatementRole);
				}
				script.Replace (foreachStatement, forStatement);
				script.Link (initializer.Variables.First ().NameToken, id1, id2, id3);
			});
		}

			public override object Visit (For forStatement)
			{
				var result = new ForStatement ();
				
				var location = LocationsBag.GetLocations (forStatement);
				
				result.AddChild (new CSharpTokenNode (Convert (forStatement.loc), "for".Length), ForStatement.Roles.Keyword);
				if (location != null)
					result.AddChild (new CSharpTokenNode (Convert (location[0]), 1), ForStatement.Roles.LPar);
				if (forStatement.InitStatement != null)
					result.AddChild ((INode)forStatement.InitStatement.Accept (this), ForStatement.Roles.Initializer);
				if (location != null)
					result.AddChild (new CSharpTokenNode (Convert (location[1]), 1), ForStatement.Roles.Semicolon);
				if (forStatement.Test != null)
					result.AddChild ((INode)forStatement.Test.Accept (this), ForStatement.Roles.Condition);
				if (location != null)
					result.AddChild (new CSharpTokenNode (Convert (location[2]), 1), ForStatement.Roles.Semicolon);
				if (forStatement.Increment != null)
					result.AddChild ((INode)forStatement.Increment.Accept (this), ForStatement.Roles.Iterator);
				if (location != null)
					result.AddChild (new CSharpTokenNode (Convert (location[3]), 1), ForStatement.Roles.RPar);
				
				result.AddChild ((INode)forStatement.Statement.Accept (this), ForStatement.Roles.EmbeddedStatement);
				
				return result;
			}

		public virtual void VisitForStatement (ForStatement forStatement)
		{
			VisitChildren (forStatement);
		}

			void AddStatementOrList(ForStatement forStatement, Mono.CSharp.Statement init, Role<Statement> role)
			{
				if (init == null)
					return;
				var stmtList = init as StatementList;
				if (stmtList != null) {
					foreach (var stmt in stmtList.Statements) {
						forStatement.AddChild((Statement)stmt.Accept(this), role);
					}
				} else if (init is Mono.CSharp.EmptyStatement) {
					
				} else {
					forStatement.AddChild((Statement)init.Accept(this), role);
				}
			}

 // ForStatement
 public override bool Walk(ForStatement node) { return false; }

		public override void VisitForStatement(ForStatement forStatement) {
			// Initializer. In case we need more than one statement, put all other statements just before this loop.
			JsStatement initializer;
			if (forStatement.Initializers.Count == 1 && forStatement.Initializers.First() is VariableDeclarationStatement) {
				forStatement.Initializers.First().AcceptVisitor(this);
				initializer = _result[_result.Count - 1];
				_result.RemoveAt(_result.Count - 1);
			}
			else {
				JsExpression initExpr = null;
				foreach (var init in forStatement.Initializers) {
					var compiledInit = CompileExpression(((ExpressionStatement)init).Expression, CompileExpressionFlags.None);
					if (compiledInit.AdditionalStatements.Count == 0) {
						initExpr = (initExpr != null ? JsExpression.Comma(initExpr, compiledInit.Expression) : compiledInit.Expression);
					}
					else {
						if (initExpr != null)
							_result.Add(initExpr);
						_result.AddRange(compiledInit.AdditionalStatements);
						initExpr = compiledInit.Expression;
					}
				}
				initializer = (initExpr != null ? (JsStatement)initExpr : JsStatement.Empty);
			}

			// Condition
			JsExpression condition;
			List<JsStatement> preBody = null;
			if (!forStatement.Condition.IsNull) {
				var compiledCondition = CompileExpression(forStatement.Condition, CompileExpressionFlags.ReturnValueIsImportant);
				if (compiledCondition.AdditionalStatements.Count == 0) {
					condition = compiledCondition.Expression;
				}
				else {
					// The condition requires additional statements. Transform "for (int i = 0; i < (SomeProperty = 1); i++) { ... }" to "for (var i = 0;; i++) { this.set_SomeProperty(1); if (!(i < 1)) { break; } ... }
					preBody = new List<JsStatement>();
					preBody.AddRange(compiledCondition.AdditionalStatements);
					preBody.Add(JsStatement.If(JsExpression.LogicalNot(compiledCondition.Expression), JsStatement.Break(), null));
					condition = null;
				}
			}
			else {
				condition = null;
			}

			// Iterators
			JsExpression iterator = null;
			List<JsStatement> postBody = null;
			if (forStatement.Iterators.Count > 0) {
				var compiledIterators = forStatement.Iterators.Select(i => CompileExpression(((ExpressionStatement)i).Expression, CompileExpressionFlags.None)).ToList();
				if (compiledIterators.All(i => i.AdditionalStatements.Count == 0)) {
					// No additional statements are required, add them as a single comma-separated expression to the JS iterator.
					iterator = compiledIterators.Aggregate(iterator, (current, i) => (current != null ? JsExpression.Comma(current, i.Expression) : i.Expression));
				}
				else {
					// At least one of the compiled iterators need additional statements. We could add the last expressions that don't need extra statements to the iterators section of the for loop, but for simplicity we'll just add everything to the end of the loop.
					postBody = new List<JsStatement>();
					foreach (var i in compiledIterators) {
						postBody.AddRange(i.AdditionalStatements);
						postBody.Add(i.Expression);
					}
				}
			}

			// Body
			var body = CreateInnerCompiler().Compile(forStatement.EmbeddedStatement);

			if (preBody != null || postBody != null) {
				body = JsStatement.Block(((IEnumerable<JsStatement>)preBody ?? new JsStatement[0]).Concat(body.Statements).Concat((IEnumerable<JsStatement>)postBody ?? new JsStatement[0]));
			}

			_result.Add(JsStatement.For(initializer, condition, iterator, body));
		}

 /**
  * Call back method that must be called when the given <code>ForStatement
  * </code> will become the next <i>traverse candidate</i>.
  *
  * @param pForStatement  The <code>ForStatement</code> object that will
  *                       become the next <i>traverse candidate</i>.
  */
 public void performAction(
      ForStatement pForStatement)
 {
     // Nothing to do.
 }

		public override void VisitForStatement(ForStatement forStatement)
		{
			foreach (AstNode node in forStatement.Children) {
				if (node.Role == Roles.Semicolon) {
					if (node.NextSibling is CSharpTokenNode || node.NextSibling is EmptyStatement) {
						continue;
					}
					ForceSpacesBefore(node, policy.SpaceBeforeForSemicolon);
					ForceSpacesAfter(node, policy.SpaceAfterForSemicolon);
				}
			}

			ForceSpacesBefore(forStatement.LParToken, policy.SpaceBeforeForParentheses);

			ForceSpacesAfter(forStatement.LParToken, policy.SpacesWithinForParentheses);
			ForceSpacesBefore(forStatement.RParToken, policy.SpacesWithinForParentheses);

			FixEmbeddedStatment(policy.StatementBraceStyle, policy.ForBraceForcement, forStatement.EmbeddedStatement);
		}

 public void VisitFor(ForStatement f)
 {
     w.Write("for");
     w.Write(" ");
     f.exprs.Write(writer);
     w.Write(" ");
     w.Write("in");
     w.Write(" ");
     f.tests.Write(writer);
     w.WriteLine(":");
     ++w.IndentLevel;
     f.Body.Accept(this);
     --w.IndentLevel;
 }

		public override IEnumerable<CodeAction> GetActions(RefactoringContext context)
		{
			bool hasIndexAccess;
			var foreachStatement = GetForeachStatement(context, out hasIndexAccess);
			if (foreachStatement == null || foreachStatement.EmbeddedStatement == null)
				yield break;
			var state = context.GetResolverStateBefore (foreachStatement.EmbeddedStatement);
			string name = GetName(state, VariableNames);
			if (name == null) // very unlikely, but just in case ...
				yield break;

			yield return new CodeAction(context.TranslateString("Convert 'foreach' loop to 'for'"), script => {
				var result = context.Resolve(foreachStatement.InExpression);
				var countProperty = GetCountProperty(result.Type);
				var inExpression = foreachStatement.InExpression;

				var initializer = hasIndexAccess ? new VariableDeclarationStatement(new PrimitiveType("int"), name, new PrimitiveExpression(0)) :
				                  new VariableDeclarationStatement(new SimpleType("var"), name, new InvocationExpression(new MemberReferenceExpression (inExpression.Clone (), "GetEnumerator")));
				var id1 = new IdentifierExpression(name);
				var id2 = id1.Clone();
				var id3 = id1.Clone();
				Statement declarationStatement = null;
				if (inExpression is ObjectCreateExpression || inExpression is ArrayCreateExpression) {
					string listName = GetName(state, CollectionNames) ?? "col";
					declarationStatement = new VariableDeclarationStatement (
						new PrimitiveType ("var"),
						listName,
						inExpression.Clone ()
					);
					inExpression = new IdentifierExpression (listName);
				}

				var variableDeclarationStatement = new VariableDeclarationStatement(
					foreachStatement.VariableType.Clone(),
					foreachStatement.VariableName,
					hasIndexAccess ? (Expression)new IndexerExpression(inExpression.Clone(), id3) : new MemberReferenceExpression(id1, "Current")
				);

				var forStatement = new ForStatement {
					Initializers = { initializer },
					Condition = hasIndexAccess ? (Expression)new BinaryOperatorExpression (id1, BinaryOperatorType.LessThan, new MemberReferenceExpression (inExpression.Clone (), countProperty)) :
					            new InvocationExpression(new MemberReferenceExpression (id2, "MoveNext")),
					EmbeddedStatement = new BlockStatement {
						variableDeclarationStatement
					}
				};

				if (hasIndexAccess)
					forStatement.Iterators.Add(new UnaryOperatorExpression (UnaryOperatorType.PostIncrement, id2));

				if (foreachStatement.EmbeddedStatement is BlockStatement) {
					variableDeclarationStatement.Remove();
					var oldBlock = (BlockStatement)foreachStatement.EmbeddedStatement.Clone();
					if (oldBlock.Statements.Any()) {
						oldBlock.Statements.InsertBefore(oldBlock.Statements.First(), variableDeclarationStatement);
					} else {
						oldBlock.Statements.Add(variableDeclarationStatement);
					}
					forStatement.EmbeddedStatement = oldBlock;
				} else {
					forStatement.EmbeddedStatement.AddChild (foreachStatement.EmbeddedStatement.Clone (), BlockStatement.StatementRole);
				}
				if (declarationStatement != null)
					script.InsertBefore (foreachStatement, declarationStatement);
				script.Replace (foreachStatement, forStatement);
				if (hasIndexAccess) {
					script.Link (initializer.Variables.First ().NameToken, id1, id2, id3);
				} else {
					script.Link (initializer.Variables.First ().NameToken, id1, id2);
				}
			}, foreachStatement);

			if (!hasIndexAccess)
				yield break;
			yield return new CodeAction(context.TranslateString("Convert 'foreach' loop to optimized 'for'"), script => {
				var result = context.Resolve(foreachStatement.InExpression);
				var countProperty = GetCountProperty(result.Type);

				var initializer = new VariableDeclarationStatement(new PrimitiveType("int"), name, new PrimitiveExpression(0));
				var id1 = new IdentifierExpression(name);
				var id2 = id1.Clone();
				var id3 = id1.Clone();
				var inExpression = foreachStatement.InExpression;
				Statement declarationStatement = null;
				if (inExpression is ObjectCreateExpression || inExpression is ArrayCreateExpression) {
					string listName = GetName(state, CollectionNames) ?? "col";
					declarationStatement = new VariableDeclarationStatement (
						new PrimitiveType ("var"),
						listName,
						inExpression.Clone ()
						);
					inExpression = new IdentifierExpression (listName);
				}

				var variableDeclarationStatement = new VariableDeclarationStatement(
					foreachStatement.VariableType.Clone(),
					foreachStatement.VariableName,
					new IndexerExpression(inExpression.Clone(), id3)
					);

//.........这里部分代码省略.........

 private void GenerateForTuple(ForStatement f, List<Exp> ids)
 {
     var localVar = GenSymLocalTuple();
     var v = f.tests.Accept(xlat);
     gen.Foreach(localVar, v, () =>
     {
         EmitTupleFieldAssignments(ids, localVar);
         f.Body.Accept(this);
     });
 }