static int opr_handler(struct calc *calc)
{
assert(calc != NULL);
char c = *calc->cur;
opr_advance(calc);
/* 如果操作符栈是空栈的话就压栈 */
if (STACK_IS_EMPTY(calc->opr)) {
OPR_PUSH(c);
return 0;
}
/* 如果操作符栈非空， 且该操作符优先级高于栈顶运算符就压栈 */
char top_c = 0;
if (OPR_TOP(top_c) < 0) {
fprintf(stderr, "Error: opr top failed.\n");
return -1;
}
while(1) {
if (opr2level(c) > opr2level(top_c) || STACK_IS_EMPTY(calc->opr)) {
OPR_PUSH(c);
return 0;
}
if (do_operate(calc) < 0) {
fprintf(stderr, "Error: do operate failed.\n");
return -1;
}
if ( !STACK_IS_EMPTY(calc->opr) && OPR_TOP(top_c) < 0) {
fprintf(stderr, "Error: while opr top failed.\n");
return -1;
}
}
return 0;
}
static int opr_handler(struct calc *calc)
{
assert(calc != NULL);
char c = *calc->cur;
int zero = 0;
if (calc->pre_flag == F_NUM) {
calc->pre_flag = F_OPR;
} else if (calc->pre_flag == F_OPR) {
if (c == '-') {
NUM_PUSH(zero);
OPR_PUSH(c);
calc->pre_flag = F_OPR;
return 0;
} else if (c == '+') {
return 0;
}
} else {
fprintf(stderr, "unknow character\n");
return -2;
}
/* 如果操作符栈是空栈的话就压栈 */
if (STACK_IS_EMPTY(calc->opr)) {
OPR_PUSH(c);
return 0;
}
/* 如果操作符栈非空， 且该操作符优先级高于栈顶运算符就压栈 */
char top_c = 0;
if (OPR_TOP(top_c) < 0) {
fprintf(stderr, "Error: opr top failed.\n");
return -1;
}
while(1) {
if (opr2level(c) > opr2level(top_c) || STACK_IS_EMPTY(calc->opr)) {
OPR_PUSH(c);
return 0;
}
if (do_operate(calc) < 0) {
fprintf(stderr, "Error: do operate failed.\n");
return -1;
}
if ( !STACK_IS_EMPTY(calc->opr) && OPR_TOP(top_c) < 0) {
fprintf(stderr, "Error: while opr top failed.\n");
return -1;
}
}
return 0;
}
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;
}
static int right_bracket_handler(struct calc *calc)
{
assert(calc != NULL);
char c;
while(1) {
if (OPR_TOP(c) < 0) {
fprintf(stderr, "Error: opr top failed\n");
return -1;
}
if (c == '(') {
if (OPR_POP(c) < 0) {
fprintf(stderr, "Error: opr pop failed\n");
return -1;
}
return 0;
}
if (do_operate(calc) < 0) {
fprintf(stderr, "Error: do operate failed.\n");
return -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;
}
