%x COMMENT
%x STRING

%%
<INITIAL>"--"   {       BEGIN(COMMENT); }
<INITIAL>\"     { ECHO; BEGIN(STRING);  }
<COMMENT>"\n"   { ECHO; BEGIN(INITIAL); }
<STRING>\\\"    { ECHO; }
<STRING>\"      { ECHO; BEGIN(INITIAL); }

<INITIAL>.      { ECHO; }
<COMMENT>.      {       }
<STRING>.       { ECHO; }
%%

// https://westes.github.io/flex/manual/Start-Conditions.html

#include <stdlib.h>

int main(void) {
    
    yylex();

    return EXIT_SUCCESS;
}