Flex++不好的字符错误等等。新的flex

we are just getting started using flex to build a lexer for a project, but we cant figure out how to get it to work. I copy the example code given in tutorials and try to run flex++ with the tut file as its argument however I just receive an error each time. e.g.

我们刚刚开始使用flex为一个项目构建一个lexer，但是我们不知道如何让它工作。我复制了教程中给出的示例代码，并尝试使用tut文件运行flex++，但是每次都只接收一个错误。如。

input file (calc.l)

输入文件(calc.l)

%name Scanner
%define IOSTREAM

DIGIT   [0-9]
DIGIT1  [1-9]

%%

"+"               { cout << "operator <" << yytext[0] << ">" << endl; }
"-"               { cout << "operator <" << yytext[0] << ">" << endl; }
"="               { cout << "operator <" << yytext[0] << ">" << endl; }
{DIGIT1}{DIGIT}*  { cout << "  number <" << yytext    << ">" << endl; }
.                 { cout << " UNKNOWN <" << yytext[0] << ">" << endl; }

%%

int main(int argc, char ** argv)
{
    Scanner scanner;
    scanner.yylex();
    return 0;
}

with this code i get

我得到了这个代码。

flex++ calc.l
calc.l:1: bad character: % calc.l:1: unknown error processing section 1
calc.l:1: unknown error processing section 1
calc.l:1: unknown error processing section 1
calc.l:2: unrecognised '%' directive

1:未知错误处理第1节calc.l:1:未知错误处理第1节calc.l:1:未知错误处理第1节calc.l:2:未确认的“%”指令。

could anyone help me understand what im doing wrong here? cheers

有人能帮我理解我在这里做错了什么吗?干杯

2 个解决方案

#1

You might try something like:

你可以试试:

adding %{ ... %} to the first couple of lines in your file
添加% {…%}在您的文件的前几行。
adding #include <iostream> and using namespace std; (instead of trying to define Scanner)
添加#包括和使用名称空间std;(而不是试图定义扫描仪)
adding %option noyywrap above the rules section
在规则部分中添加%选项noyywrap。
using just yylex() (instead of trying to call the method of a non-existant Scanner)
使用yylex()(而不是尝试调用非存在扫描器的方法)

With your example, it could look something like this:

举个例子，它可以是这样的:

%{
#include <iostream>
using namespace std;
%}

DIGIT   [0-9]
DIGIT1  [1-9]

/* read only one input file */
%option noyywrap

%%
"+"               { cout << "operator <" << yytext[0] << ">" << endl; }
"-"               { cout << "operator <" << yytext[0] << ">" << endl; }
"="               { cout << "operator <" << yytext[0] << ">" << endl; }
{DIGIT1}{DIGIT}*  { cout << "  number <" << yytext    << ">" << endl; }
.                 { cout << " UNKNOWN <" << yytext[0] << ">" << endl; }
%%

int main(int argc, char** argv)
{
    yylex();
    return 0;
}

#2

What is the version of flex++ you using? I uses 'Function: fast lexical analyzer generator C/C++ V2.3.8-7 (flex++), based on 2.3.8 and modified by coetmeur@icdc.fr for c++' (-? option) and your cacl.c is processed perfectly..

你使用的flex++的版本是什么?我使用了“功能:快速词汇分析器生成器C/ c++ V2.3.8-7 (flex++)，基于2.3.8，并由coetmeur@icdc.fr修改为c++”(-?选项)和cacl。c处理完美. .

For Win32, this version of Flex++/Bison++ is here

对于Win32，这个版本的Flex++/Bison++在这里。

#1