STATIC mp_obj_t stm_mem_subscr(mp_obj_t self_in, mp_obj_t index, mp_obj_t value) {
// TODO support slice index to read/write multiple values at once
stm_mem_obj_t *self = self_in;
if (value == MP_OBJ_NULL) {
// delete
return MP_OBJ_NULL; // op not supported
} else if (value == MP_OBJ_SENTINEL) {
// load
uint32_t addr = get_read_addr(index, self->elem_size);
uint32_t val;
switch (self->elem_size) {
case 1: val = (*(uint8_t*)addr); break;
case 2: val = (*(uint16_t*)addr); break;
default: val = (*(uint32_t*)addr); break;
}
return mp_obj_new_int(val);
} else {
// store
uint32_t addr = get_write_addr(index, self->elem_size);
uint32_t val = mp_obj_get_int(value);
switch (self->elem_size) {
case 1: (*(uint8_t*)addr) = val; break;
case 2: (*(uint16_t*)addr) = val; break;
default: (*(uint32_t*)addr) = val; break;
}
return mp_const_none;
}
}
void write(symbol_t value) {
physical_cell_t* write_addr = get_write_addr();
physical_goto(write_addr);
physical_write_current(value);
// The read pointer now points to the cell we just wrote
*virtual_current = write_addr;
}
int main() {
int i; // Counter variable - removes a gcc warning
init();
for (i = 0; i < rules_num; i++) {
#define rule (rules[0])
// Discard state mismatches
if (rule.state_in != ANY && rule.state_in != state)
continue;
// Discard symbol mismatches
if (rule.symbol_in != '*' && rule.symbol_in != read())
continue;
// State change
if (rule.state_out != ANY)
state = rule.state_out;
// Symbol change
if (rule.symbol_out != '*') {
write(rule.symbol_out);
}
// Tape movement
assert(rule.direction == 'r' || rule.direction == 'l' || rule.direction == '*');
switch (rule.direction) {
case 'r':
virtualMove(RIGHT);
break;
case 'l':
virtualMove(LEFT);
break;
case '*':
// Do nothing
break;
}
break;
}
printf("Final state: %i\n", state);
printf("Final position on the (virtual) tape: %i\n", virtual_current - virtual_tape);
printf("Final symbol on the tape: %i (%c)\n", read(), read());
printf("-----\nStatistics\n");
printf("Physical tape length: %i\n", get_write_addr() - physical_tape);
return 0;
}