include/cvaluate/TokenStream.h

/*
* Copyright 2020 The casbin Authors. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
*    http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/

#ifndef CVALUATE_TOKEN_STREAM
#define CVALUATE_TOKEN_STREAM

#include "./Token.h"

namespace Cvaluate {
    class TokenStream {
        private:
            std::vector<ExpressionToken> tokens;
            std::vector<ExpressionToken>::iterator index;
        public:
            TokenStream(std::vector<ExpressionToken> _tokens) : tokens(_tokens) {
                this->index = tokens.begin();
            };

            void Rewind() {
                this->index -= 1;
            }

            std::vector<ExpressionToken>::iterator Next() {
                this->index += 1;
                return this->index - 1;
            }

            bool HasNext() {
                return this->index < this->tokens.end();
            }
    };
} // Cvaluate   

#endif