static int bracket_handle(struct calc_info *info)
{
assert(info != NULL);
char opr = *info->cur;
switch (opr) {
case '(':
OPR_PUSH(opr);
break;
case ')':
{
char top_c;
while (1) {
if (OPR_TOP(top_c) < 0) {
fprintf(stderr, "Error:缺少左括号\n");
goto err_miss_left_bracket;
}
if (top_c == '(') {
OPR_POP(top_c); goto out;
} else {
do_stack(info);
}
}
}
default:
break;
}
out:
return 0;
err_miss_left_bracket:
return -1;
}
static int opr_handle(struct calc_info *info)
{
assert(info != NULL);
char c = *info->cur;
if (info->flag == NUM) {
info->flag = OPR;
} else {
switch (c) {
case '+':
goto out;
break;
case '-':
//FIXME 负号的处理
{
num_t zero = 0;
NUM_PUSH(zero);
OPR_PUSH(c);
goto out;
}
break;
default:
fprintf(stderr, "免费版不支持多个运算符\n");
break;
}
}
//1. 入栈的两种情况： a) 空栈 b）运算符优先级高于栈顶运算符
if (OPR_IS_EMPTY) {
OPR_PUSH(c);
} else {
char top_c;
while (1) {
//a 空栈
if (OPR_TOP(top_c) < 0) {
OPR_PUSH(c);
break;
}
//b 优先级高于栈顶
if (opr2level(c) > opr2level(top_c)) {
OPR_PUSH(c);
break;
} else {
if (do_stack(info) < 0) {
fprintf(stderr,"do_stack failed\n");
goto err_do_stack;
}
}
}
}
out:
return 0;
err_do_stack:
return -1;
}
int main(int argc, char *argv[])
{
if (argc < 2) argv[argc++] = ".";
if (argc > 2 && strcmp(argv[2], "-r") == 0) {
printf("递归处理: %s\n", argv[1]);
do_recuerse(argv[1]);
} else if (argc > 2 && strcmp(argv[2], "-s") == 0) {
printf("非递归处理: %s\n", argv[1]);
do_stack(argv[1]);
} else {
printf("调用函数: %s\n", argv[1]);
do_nftw(argv[1]);
}
return 0;
}
static num_t calc_main(struct calc_info *info, const char *expr)
{
assert(info != NULL);
assert(expr != NULL);
info->cur = expr;
int iret = 0;
for (; *info->cur != '\0'; info->cur++) {
switch (*info->cur) {
case '0' ... '9':
if ((iret = num_handle(info)) < 0) {
fprintf(stderr, "num_handle failed\n");
return iret;
}
break;
case '+':
case '-':
case '*':
case '/':
case '%':
if ((iret = opr_handle(info)) < 0) {
fprintf(stderr, "opr_handle failed\n");
return iret;
}
break;
case ' ':
case '\n':
case '\t':
break;
case '(':
case ')':
if ((iret = bracket_handle(info)) < 0) {
fprintf(stderr, "bracket_handle failed\n");
return iret;
}
break;
default:
fprintf(stderr, "unkown char '%c'\n", *info->cur);
goto err_unkown_char;
}
}
num_t ret = 0;
while (!OPR_IS_EMPTY) {
char top_c = 0;
OPR_TOP(top_c);
if (top_c == '(') {
fprintf(stderr, "Error: 缺少对应的右括号\n");
goto err_miss_right_bracket;
}
if (do_stack(info) < 0) {
fprintf(stderr, "do_stack failed\n");
goto err_do_stack;
}
}
NUM_POP(ret);
return ret;
err_unkown_char:
return -1;
err_do_stack:
return -2;
err_miss_right_bracket:
return -3;
}
