能读入语法文件

根据语法文件创建语法数据结构：
*********************************************************************************************
grammar_table -> generator -> right_generator -> generator_symbol -> grammar_symbol -> char *
                     |               |                   |
                 generator ->       ...
                     |
                 generator ->       ...
                     |
                 generator ->       ...
*********************************************************************************************
generator -> right_generator -> generator_symbol -> grammar_symbol -> char *
                    |                   |
             right_generator ->        ...
                    |
             right_generator ->        ...
                    |
             right_generator ->        ...
*********************************************************************************************
right_generator -> generator_symbol -> grammar_symbol -> char *
                           |
                   generator_symbol -> grammar_symbol -> char *
                           |
                   generator_symbol -> grammar_symbol -> char *
                           |
                   generator_symbol -> grammar_symbol -> char *
*********************************************************************************************
grammar_symbol_table -> grammar_symbol -> char *
                              |
                        grammar_symbol -> char *
                              |
                        grammar_symbol -> char *
                              |
                        grammar_symbol -> char *
*********************************************************************************************