#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#define TOKENS "><+-.,[]"
#define CODE_SEGMENT_SIZE 30000
#define STACK_SEGMENT_SIZE 1000
#define DATA_SEGMENT_SIZE 30000
typedef void (*Callback)(void);
struct {
char cs[CODE_SEGMENT_SIZE]; /* Code Segment */
long ip; /* Instruction Pointer */
char ss[STACK_SEGMENT_SIZE]; /* Stack Segment */
long sp; /* Stack Pointer */
char ds[DATA_SEGMENT_SIZE]; /* Data Segment */
long bp; /* Base Pointer */
Callback fn[128];
} vm;
void vm_forward() {
vm.bp = (vm.bp + 1) % DATA_SEGMENT_SIZE;
}
void vm_backward() {
vm.bp = (vm.bp + DATA_SEGMENT_SIZE - 1) % DATA_SEGMENT_SIZE;
}
void vm_increment() {
vm.ds[vm.bp]++;
}
void vm_decrement() {
vm.ds[vm.bp]--;
}
void vm_input() {
vm.ds[vm.bp] = getchar();
}
void vm_output() {
putchar(vm.ds[vm.bp]);
}
void vm_while_entry() {
if (vm.ds[vm.bp]) {
vm.ss[vm.sp] = vm.ip - 1;
vm.sp++;
} else {
int c = 1;
for (vm.ip++; vm.cs[vm.ip] && c; vm.ip++) {
if (vm.cs[vm.ip] == '[') {
c++;
} else if (vm.cs[vm.ip] == ']') {
c--;
}
}
}
}
void vm_while_exit() {
if (vm.ds[vm.bp]) {
vm.sp--;
vm.ip = vm.ss[vm.sp];
}
}
void setup() {
int c;
int i;
memset(&vm, 0, sizeof(vm));
vm.fn['>'] = vm_forward;
vm.fn['<'] = vm_backward;
vm.fn['+'] = vm_increment;
vm.fn['-'] = vm_decrement;
vm.fn['.'] = vm_output;
vm.fn[','] = vm_input;
vm.fn['['] = vm_while_entry;
vm.fn[']'] = vm_while_exit;
for (i = 0; (c = getchar()) != EOF;) {
if (strchr(TOKENS, c)) {
vm.cs[i] = c;
i++;
}
}
}
void run() {
while (vm.cs[vm.ip]) {
vm.fn[vm.cs[vm.ip]]();
vm.ip++;
}
}
int main(int argc, char* argv[]) {
if (argc > 1) {
freopen(argv[1], "r", stdin);
}
setup();
run();
return 0;
}
Note that non-ascii characters in the above source code will be escaped (such as \x9f).