private Stmt ForStatement()
        {
            Consume(TokenType.LeftParen, "Expect '(' after 'for'.");

            Stmt initializer;

            if (Match(TokenType.Semicolon))
            {
                initializer = null;
            }
            else if (Match(TokenType.Var))
            {
                initializer = VarDeclaration();
            }
            else
            {
                initializer = ExpressionStatement();
            }

            Expr condition = null;

            if (!Check(TokenType.Semicolon))
            {
                condition = Expression();
            }
            Consume(TokenType.Semicolon, "Expect ';' after loop condition.");

            Expr increment = null;

            if (!Check(TokenType.RightParen))
            {
                increment = Expression();
            }
            Consume(TokenType.RightParen, "Expect ')' after for clauses.");

            var body = Statement();

            if (increment != null)
            {
                body = new BlockStmt(new List <Stmt> {
                    body, new ExpressionStmt(increment)
                });
            }

            if (condition == null)
            {
                condition = new LiteralExpr(true);
            }
            body = new WhileStmt(condition, body);

            if (initializer != null)
            {
                body = new BlockStmt(new List <Stmt> {
                    initializer, body
                });
            }

            return(body);
        }
 public void VisitBlockStmt(BlockStmt stmt)
 {
     BeginScope();
     Resolve(stmt.Statements);
     EndScope();
 }
 public void VisitBlockStmt(BlockStmt stmt)
 {
     ExecuteBlock(stmt.Statements, new Environment(environment));
 }