示例#1
0
        public object VisitFunctionStmt(Function stmt)
        {
            var function = new LoxFunction(stmt, _environment, false);

            _environment.Define(stmt.Name.Lexeme, function);
            return(null);
        }
示例#2
0
        public object VisitClassStmt(Class stmt)
        {
            object superclass = null;

            if (stmt.Superclass != null)
            {
                superclass = Evaluate(stmt.Superclass);
                if (!(superclass is LoxClass))
                {
                    throw new RuntimeError(stmt.Superclass.Name, "Superclass must be a class.");
                }
            }

            _environment.Define(stmt.Name.Lexeme, null);

            if (stmt.Superclass != null)
            {
                _environment = new Environment(_environment);
                _environment.Define("super", superclass);
            }

            var methods = new Dictionary <string, LoxFunction>();

            foreach (var method in stmt.Methods)
            {
                var isInitializer = method.Name.Lexeme == "init";
                var function      = new LoxFunction(method, _environment, isInitializer);
                methods.Add(method.Name.Lexeme, function);
            }

            var klass = new LoxClass(stmt.Name.Lexeme, (LoxClass)superclass, methods);

            if (superclass != null)
            {
                _environment = _environment.Enclosing;
            }

            _environment.Assign(stmt.Name, klass);
            return(null);
        }