switch(*s) {
case '\\': if(o) o[len] = '\\';s++;len++; break;
case '"': if(o) o[len] = '"';s++;len++; break;
+ case '\'': if(o) o[len] = '\'';s++;len++; break;
case 'b': if(o) o[len] = '\b';s++;len++; break;
case 'f': if(o) o[len] = '\f';s++;len++; break;
case 'n': if(o) o[len] = '\n';s++;len++; break;