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我在 C++ 中有一个手写的解析器，其中包含一个next_token()方法，我想在里面使用它yylex()（我已经用 Bison 的 C API 正确地做到了这一点，但想使用动态类型，所以转移到了 C++）。我阅读了文档的这些部分，阅读了示例并尝试了两个现有签名，但仍然无法正确执行...

解析器.yy：

%require "3.2"
%language "c++"
%define api.value.type variant
%define api.token.constructor
%define parse.assert
%code requires
{
    #include <iostream>
    #include <string>
}


%code{
    yy::parser::symbol_type yy::parser::yylex();
    void yy::parser::yyerror(const char *error);
}

%token VAR COL ITYPE
%token IDENTIFIER
%token INTEGER
%token EOL

%type <std::string> type PrimitiveType IDENTIFIER
%type <int> INTEGER    

%%
program:
| program EOL
| program SimpleDeclaration {  }
;

SimpleDeclaration: VariableDeclaration
;

VariableDeclaration: VAR IDENTIFIER COL type {std::cout<<"defined variable " << $2 << " with type " << $4 << std::endl; }

type: IDENTIFIER
| PrimitiveType
;

PrimitiveType: ITYPE { $$ = "int"; }
;

%%
void yy::parser::yyerror(const std::string& m)
{
    std::cout << "syntax error" << std::endl;
}
// also 'yy::parser::symbol_type yy::parser::yylex(semantic_type* yylval)' does the same
int yy::parser::yylex(semantic_type* yylval)
{
    return 0; // just returning a zero for now
}


int main()
{
    yy::parser p;
    return 0;
}

错误：

bison -d parser.ypp
g++ -std=c++17 -o foobar parser.tab.cpp
parser.ypp:14:29: error: no declaration matches ‘yy::parser::symbol_type yy::parser::yylex()’
   14 |     yy::parser::symbol_type yy::parser::yylex();
      |                             ^~
parser.ypp:14:29: note: no functions named ‘yy::parser::symbol_type yy::parser::yylex()’
In file included from parser.tab.cpp:41:
parser.tab.hpp:193:9: note: ‘class yy::parser’ defined here
  193 |   class parser
      |         ^~~~~~
parser.ypp:15:10: error: no declaration matches ‘void yy::parser::yyerror(const char*)’
   15 |     void yy::parser::yyerror(const char *error);
      |          ^~
parser.ypp:15:10: note: no functions named ‘void yy::parser::yyerror(const char*)’
In file included from parser.tab.cpp:41:
parser.tab.hpp:193:9: note: ‘class yy::parser’ defined here
  193 |   class parser
      |         ^~~~~~
parser.tab.cpp: In member function ‘virtual int yy::parser::parse()’:
parser.tab.cpp:453:38: error: ‘yylex’ was not declared in this scope; did you mean ‘yylen’?
  453 |             symbol_type yylookahead (yylex ());
      |                                      ^~~~~
      |                                      yylen
parser.ypp: At global scope:
parser.ypp:45:6: error: no declaration matches ‘void yy::parser::yyerror(const string&)’
   45 | void yy::parser::yyerror(const std::string& m)
      |      ^~
parser.ypp:45:6: note: no functions named ‘void yy::parser::yyerror(const string&)’
In file included from parser.tab.cpp:41:
parser.tab.hpp:193:9: note: ‘class yy::parser’ defined here
  193 |   class parser
      |         ^~~~~~
parser.ypp:50:5: error: no declaration matches ‘int yy::parser::yylex(yy::parser::semantic_type*)’
   50 | int yy::parser::yylex(semantic_type* yylval)
      |     ^~
parser.ypp:50:5: note: no functions named ‘int yy::parser::yylex(yy::parser::semantic_type*)’
In file included from parser.tab.cpp:41:
parser.tab.hpp:193:9: note: ‘class yy::parser’ defined here
  193 |   class parser
      |         ^~~~~~

我也觉得很奇怪，即使没有覆盖，它似乎yylex也在这里使用（即使我不尝试覆盖也会导致错误出现）：

parser.tab.cpp: In member function ‘virtual int yy::parser::parse()’:
parser.tab.cpp:453:38: error: ‘yylex’ was not declared in this scope; did you mean ‘yylen’?
  453 |             symbol_type yylookahead (yylex ());
      |                                      ^~~~~
      |                                      yylen

我在这里做错了什么？提前致谢

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0 回答 0