正则表达式匹配字符串 [英] Regex matching string

问题描述

我正在实现一个编译器，我想做的一件事是使用'+'进行字符串连接，例如:

I am implementing a compiler and one thing I'd like to do is the string concatenation using '+', eg:

str_cnct = "hi" + "dear"

所以现在的值是"hidear".

So the value now is "hidear".

问题是我在flex中的正则表达式直接将所有正则表达式捕获为一个字符串，给出"hi + dear". 我当前的正则表达式是:\".*\"

The problem is that my regex in flex captures all of it directly as a string giving "hi + dear". My current regex is: \".*\"

{string}                {
                            yylval.struct_val.val.chain = (char *)malloc(sizeof(char)*yyleng);
                            strncpy(yylval.struct_val.val.chain,yytext,yyleng);
                            remove_char(yylval.struct_val.val.chain);
                            yylval.struct_val.length = yyleng;
                            yylval.struct_val.line = yylineno;
                            yylval.struct_val.column = columnno + yyleng + 2;
                            printf("--- String: %s\n", yylval.struct_val.val.chain);
                            return(STRING);
                    }

如何避免这种情况，并先捕捉"hi"然后捕捉"+"作为运算符，再捕捉亲爱的"?

How to avoid this and capture "hi" then '+' as operator and then "dear"?

预先感谢

推荐答案

尝试以下操作:

^\"([^\"]*)\"\s*\+\s*\"([^\"]*)\"$

$ 1将捕获不带引号的"hi"，而$ 2将捕获不带引号的字符串"hi" +"dear"'.

$1 will capture "hi" w/o quotes and $2 will capture "dear" w/o quotes for string '"hi" + "dear"'.

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