我正在尝试使用 bisonc++ 编译以下内容：
%baseclass-preinclude <iostream>
%lsp-needed
%token NUMBER COMMENT KEYWORD VARIABLE LOGICAND LOGICOR LOGICEQUALS DOUBLELESSER
%token DOUBLEGREATER MOD LESSER GREATER OPEN CLOSE NEGATE CURLYOPEN CURLYCLOSE SEMICOLON
%left EQUALS
%left PLUS MINUS
%left TIMES
%left DIVISION
%%
start:
expressions
{
std::cout << "start -> expressions" << std::endl;
}
;
expressions:
// empty
{
std::cout << "expressions -> epsylon" << std::endl;
}
|
exp expressions
{
std::cout << "expressions -> exp expressions" << std::endl;
}
;
exp:
NUMBER
{
std::cout << "exp -> NUMBER" << std::endl;
}
|
COMMENT
{
std::cout << "exp -> COMMENT" << std::endl;
}
|
exp LOGICAND exp
{
std::cout << "exp -> exp LOGICAND exp" << std::endl;
}
|
exp LOGICOR exp
{
std::cout << "exp -> exp LOGICOR exp" << std::endl;
}
|
exp LOGICEQUALS exp
{
std::cout << "exp -> exp LOGICEQUALS exp" << std::endl;
}
|
exp DOUBLELESSER exp
{
std::cout << "exp -> exp DOUBLELESSER exp" << std::endl;
}
|
exp DOUBLEGREATER exp
{
std::cout << "exp -> exp DOUBLEGREATER exp" << std::endl;
}
|
exp PLUS exp
{
std::cout << "exp -> exp PLUS exp" << std::endl;
}
|
exp MINUS exp
{
std::cout << "exp -> exp MINUS exp" << std::endl;
}
|
exp TIMES exp
{
std::cout << "exp -> exp EQUAL exp" << std::endl;
}
|
exp EQUAL exp
{
std::cout << "exp -> exp EQUAL exp" << std::endl;
}
|
exp DIVISION exp
{
std::cout << "exp -> exp DIVISION exp" << std::endl;
}
|
exp MOD exp
{
std::cout << "exp -> exp MOD exp" << std::endl;
}
|
exp LESSER exp
{
std::cout << "exp -> exp LESSER exp" << std::endl;
}
|
exp GREATER exp
{
std::cout << "exp -> exp GREATER exp" << std::endl;
}
|
OPEN exp CLOSE
{
std::cout << "exp -> OPEN exp CLOSE" << std::endl;
}
|
NEGATE exp
{
std::cout << "exp -> NEGATE exp" << std::endl;
}
|
CURLYOPEN exp CURLYCLOSE
{
std::cout << "exp -> CURLYOPEN exp CURLYCLOSE" << std::endl;
}
|
exp SEMICOLON
{
std::cout << "exp -> SEMICOLON" << std::endl;
}
|
KEYWORD VARIABLE SEMICOLON
{
std::cout << "exp -> KEYWORD VARIABLE SEMICOLON" << std::endl;
}
;
但是，它不断返回错误
') encountered.1] Line 1: unrecognized input (`
': identifier or character-constant expected.
[bead.y: fatal] Line 23: No production rules
134950080
我显然有一些生产规则，不知道我做错了什么。我从另一个工作示例中复制了大部分代码，并根据自己的喜好对其进行了修改。怎么了？