问题描述

我正在用 ANTLR 构建一个 MySQL 语法验证器.我从 MySQL 源代码中的 sql_yacc.yy 开始，但我在转换以下语法时遇到了一些困难.我尝试了很多次，但它不起作用.有人可以帮我吗?

I am constructing a MySQL grammar validator with ANTLR. I started with the sql_yacc.yy from the MySQL source code, but I have some difficulties converting the following grammar. I tried many times, but it doesn't work. Can anyone help me?

expr
  : expr or expr 
  | expr XOR expr
  | expr and expr
  | NOT_SYM expr 
  | bool_pri IS TRUE_SYM 
  | bool_pri IS not TRUE_SYM 
  | bool_pri IS FALSE_SYM
  | bool_pri IS not FALSE_SYM 
  | bool_pri IS UNKNOWN_SYM
  | bool_pri IS not UNKNOWN_SYM 
  | bool_pri
  ;

bool_pri
  : bool_pri IS NULL_SYM 
  | bool_pri IS not NULL_SYM 
  | bool_pri EQUAL_SYM predicate 
  | bool_pri comp_op predicate
  | bool_pri comp_op all_or_any '(' subselect ')' 
  | predicate
  ;

predicate
  : bit_expr IN_SYM '(' subselect ')'
  | bit_expr not IN_SYM '(' subselect ')'
  | bit_expr IN_SYM '(' expr ')'
  | bit_expr IN_SYM '(' expr ',' expr_list ')'
  | bit_expr not IN_SYM '(' expr ')'
  | bit_expr not IN_SYM '(' expr ',' expr_list ')'
  | bit_expr BETWEEN_SYM bit_expr AND_SYM predicate
  | bit_expr not BETWEEN_SYM bit_expr AND_SYM predicate
  | bit_expr SOUNDS_SYM LIKE bit_expr
  | bit_expr LIKE simple_expr opt_escape
  | bit_expr not LIKE simple_expr opt_escape
  | bit_expr REGEXP bit_expr
  | bit_expr not REGEXP bit_expr
  | bit_expr
  ;

bit_expr
  : bit_expr '|' bit_expr 
  | bit_expr '&' bit_expr
  | bit_expr SHIFT_LEFT bit_expr 
  | bit_expr SHIFT_RIGHT bit_expr 
  | bit_expr '+' bit_expr
  | bit_expr '-' bit_expr 
  | bit_expr '+' INTERVAL_SYM expr interval 
  | bit_expr '-' INTERVAL_SYM expr interval
  | bit_expr '*' bit_expr
  | bit_expr '/' bit_expr 
  | bit_expr '%' bit_expr 
  | bit_expr DIV_SYM bit_expr 
  | bit_expr MOD_SYM bit_expr 
  | bit_expr '^' bit_expr
  | simple_expr
  ;

推荐答案

ANTLR 无法应对 left-recursion，因此没有简单的方法可以将 sql_yacc.yy 转换为 ANTLR 等效项.您可能想查看 ANTLR Wiki 中的以下资源:

ANTLR cannot cope with left-recursion, so there's no trivial way to convert sql_yacc.yy into the ANTLR equivalent. You might want to have a look at the following resources from the ANTLR Wiki:

• 左递归移除
• MySQL 方言 (ANTLR v3) 的 SQL 语法

请注意，MySQL 语法不完整，但可能会给您一个起点.

Note that the MySQL grammar is incomplete, but might give you a starting point.

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