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#include <math.h>
#include <stdio.h>
#include "state.h"
#include "util.h"
#include <stdlib.h>
#include <string.h>
#include "cmds.h"
#include <err.h>
#include <errno.h>
#define BUF_SIZE 50
/* rpncalc: a simple reverse polish notation calculator */
int main() {
/* initialize state struct and its values */
state s;
/* default input buffer is stdin */
s.defbuf = stdin;
/* default output buffer is stdout */
s.defout = stdout;
s.last_op = 0;
/* set default interactive prompt */
s.prompt = "[%d]> ";
stack stack = {{0}, 0};
/* initialize value stack */
s.stk = stack;
s.command_count = 0;
init_state(&s);
fprintf(s.defout,"welcome to rpncalc! type 'list' to see a list of commands, or 'quit' to leave.\n");
/* start reading from defbuf */
char buf[BUF_SIZE];
while(1){
fprintf(s.defout, s.prompt, s.command_count, s.last_op);
s.last_op = 0;
char *endptr = NULL;
if (s.stk.count == STACK_SIZE) errx(1, "exceeded stk size");
fgets(buf, BUF_SIZE, s.defbuf);
buf[strcspn(buf, "\n")] = 0;
double interpreted = strtod(buf, &endptr);
if (errno == ERANGE) {
fprintf(s.defout,"sorry, this number is too big\n");
continue;
}
if (interpreted == (double)0 && endptr == buf) { /* strtod returned the char it could not read */
TYPE t = discriminate(buf);
if (t == OPERATOR ) {
if (s.stk.count <= 1) {
fprintf(s.defout, "not enough arguments\n");
continue;
}
char operator = buf[0];
if (operator == '+') {
s.stk.val[s.stk.count-2] = s.stk.val[s.stk.count-1]+s.stk.val[s.stk.count-2];
s.stk.val[s.stk.count--] = 0; /* lower count by 1 */
s.last_op = '+';
} else if (operator == '-') {
s.stk.val[s.stk.count-2] = s.stk.val[s.stk.count-2]-s.stk.val[s.stk.count-1];
s.stk.val[s.stk.count--] = 0; /* lower count by 1 */
s.last_op = '-';
} else if (operator == '*') {
s.stk.val[s.stk.count-2] = s.stk.val[s.stk.count-2]*s.stk.val[s.stk.count-1];
s.stk.val[s.stk.count--] = 0; /* lower count by 1 */
s.last_op = '*';
} else if (operator == '/') {
s.stk.val[s.stk.count-2] = s.stk.val[s.stk.count-2]/s.stk.val[s.stk.count-1];
s.stk.val[s.stk.count--] = 0; /* lower count by 1 */
s.last_op = '/';
} else;
} else if (t == FUNCTION) {
/* check for special commands, else pass to exec() */
if (strcmp(buf, "quit") == 0) {
fprintf(s.defout, "quitting, bye!\n");
free (s.sorted);
exit(0);
} else if (strcmp(buf, "list") == 0) {
for (int i = 0; i < s.numel; i++) {
fprintf(s.defout, "[%s]\t->\t%s\n", s.sorted[i].name, s.sorted[i].description);
continue;
}
} else exec(buf, &s);
}
} else { /* we found a number */
s.stk.val[s.stk.count++] = interpreted;
}
s.command_count++;
for (int i = 0; i < s.stk.count; i++) {
fprintf(s.defout,"%d → %f\n",i, s.stk.val[i]);
}
}
/* free stuff */
free (s.sorted);
}
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