#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "numscan.h"

#define MAXLEN 80
#define BITS 16

#define DPRINT(f,x) printf(f,x);

static unsigned long memory[10];

#define char2index(x) (isdigit(x) ? (x) - '0' : 0)

unsigned long getnum(char *str)
{
  switch(*str) {
  case 'm':
  case 'r': return memory[char2index(str[1])];
  default:  return numscan(str);
  }
}

int main(int argc, char *argv[])
{
  unsigned long x = 0, y;
  int bits = 16;
  int mask;
  char row[MAXLEN];

  if (argc>1) sscanf(argv[1],"%d",&bits);
  printf("Using %d bits\n", bits);
  printf("Ctrl-d or q to quit\n");
  mask = ~(~0 << bits);
  while (1) {
    printf("? ");
    if (NULL==fgets(row, MAXLEN, stdin))
      exit(EXIT_SUCCESS);
    switch(row[0]) {
    case '\n':  break;
    case 'q':   exit(EXIT_SUCCESS);
    case '~':   x = ~x; break;
    case '&':   y = getnum(row+1);  x = x & y; break;
    case '|':   y = getnum(row+1);  x = x | y; break;
    case '^':   y = getnum(row+1);  x = x ^ y; break;
    case '+':   y = getnum(row+1);  x = x + y; break;
    case '-':   y = getnum(row+1);  x = x - y; break;
    case '*':   y = getnum(row+1);  x = x * y; break;
    case '/':   y = getnum(row+1);  x = x / y; break;
    case '<':   if(row[1] == '<') {
	            y = numscan(row+2);  x = x << y; break;
                } else {
                    fprintf(stderr, "syntax error\n"); break;
                }
    case '>':   if(row[1] == '>') {
                    y = numscan(row+2);  x = x >> y; break;
                } else {
	            fprintf(stderr, "syntax error\n"); break;
                }
    case 'd': case 'o': case 'x': case 'b':
    case '0': case '1': case '2': case '3': case '4': 
    case '5': case '6': case '7': case '8': case '9':
    case 'm':
                x = getnum(row); break;
    case 's':
                memory[char2index(row[1])] = x;
                break;
    default: fprintf(stderr, "unknown command %d\n", row[0]); continue;
    }
    x &= mask;
    printf("b");
    printbin(x, bits); 
    printf(", o%lo, d%lu, x%lx\n", (long) x, (long) x, (long)x);
  }

  return 0;
}