circuitpython/py/objgenerator.c

167 lines
5.3 KiB
C

#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <assert.h>
#include "nlr.h"
#include "misc.h"
#include "mpconfig.h"
#include "qstr.h"
#include "obj.h"
#include "runtime.h"
#include "bc.h"
/******************************************************************************/
/* generator wrapper */
typedef struct _mp_obj_gen_wrap_t {
mp_obj_base_t base;
mp_obj_t *fun;
} mp_obj_gen_wrap_t;
STATIC mp_obj_t gen_wrap_call(mp_obj_t self_in, uint n_args, uint n_kw, const mp_obj_t *args) {
mp_obj_gen_wrap_t *self = self_in;
mp_obj_t self_fun = self->fun;
assert(MP_OBJ_IS_TYPE(self_fun, &fun_bc_type));
int bc_n_args;
uint bc_n_state;
const byte *bc_code;
mp_obj_fun_bc_get(self_fun, &bc_n_args, &bc_n_state, &bc_code);
if (n_args != bc_n_args) {
nlr_jump(mp_obj_new_exception_msg_varg(&mp_type_TypeError, "function takes %d positional arguments but %d were given", bc_n_args, n_args));
}
if (n_kw != 0) {
nlr_jump(mp_obj_new_exception_msg(&mp_type_TypeError, "function does not take keyword arguments"));
}
return mp_obj_new_gen_instance(bc_code, bc_n_state, n_args, args);
}
const mp_obj_type_t gen_wrap_type = {
{ &mp_type_type },
.name = MP_QSTR_generator,
.call = gen_wrap_call,
};
mp_obj_t mp_obj_new_gen_wrap(mp_obj_t fun) {
mp_obj_gen_wrap_t *o = m_new_obj(mp_obj_gen_wrap_t);
o->base.type = &gen_wrap_type;
o->fun = fun;
return o;
}
/******************************************************************************/
/* generator instance */
typedef struct _mp_obj_gen_instance_t {
mp_obj_base_t base;
const byte *code_info;
const byte *ip;
mp_obj_t *sp;
uint n_state;
mp_obj_t state[];
} mp_obj_gen_instance_t;
void gen_instance_print(void (*print)(void *env, const char *fmt, ...), void *env, mp_obj_t self_in, mp_print_kind_t kind) {
print(env, "<generator object 'fun-name' at %p>", self_in);
}
mp_obj_t gen_instance_getiter(mp_obj_t self_in) {
return self_in;
}
STATIC mp_obj_t gen_next_send(mp_obj_t self_in, mp_obj_t send_value) {
mp_obj_gen_instance_t *self = self_in;
if (self->ip == 0) {
return mp_const_stop_iteration;
}
if (self->sp == self->state - 1) {
if (send_value != mp_const_none) {
nlr_jump(mp_obj_new_exception_msg(&mp_type_TypeError, "can't send non-None value to a just-started generator"));
}
} else {
*self->sp = send_value;
}
mp_vm_return_kind_t vm_return_kind = mp_execute_byte_code_2(self->code_info, &self->ip, &self->state[self->n_state - 1], &self->sp);
switch (vm_return_kind) {
case MP_VM_RETURN_NORMAL:
// Explicitly mark generator as completed. If we don't do this,
// subsequent next() may re-execute statements after last yield
// again and again, leading to side effects.
// TODO: check how return with value behaves under such conditions
// in CPython.
self->ip = 0;
if (*self->sp == mp_const_none) {
return mp_const_stop_iteration;
} else {
// TODO return StopIteration with value *self->sp
return mp_const_stop_iteration;
}
case MP_VM_RETURN_YIELD:
return *self->sp;
case MP_VM_RETURN_EXCEPTION:
default:
// TODO
assert(0);
return mp_const_none;
}
}
mp_obj_t gen_instance_iternext(mp_obj_t self_in) {
return gen_next_send(self_in, mp_const_none);
}
STATIC mp_obj_t gen_instance_send(mp_obj_t self_in, mp_obj_t send_value) {
mp_obj_t ret = gen_next_send(self_in, send_value);
if (ret == mp_const_stop_iteration) {
nlr_jump(mp_obj_new_exception(&mp_type_StopIteration));
} else {
return ret;
}
}
STATIC MP_DEFINE_CONST_FUN_OBJ_2(gen_instance_send_obj, gen_instance_send);
STATIC const mp_method_t gen_type_methods[] = {
{ "send", &gen_instance_send_obj },
{ NULL, NULL }, // end-of-list sentinel
};
const mp_obj_type_t gen_instance_type = {
{ &mp_type_type },
.name = MP_QSTR_generator,
.print = gen_instance_print,
.getiter = gen_instance_getiter,
.iternext = gen_instance_iternext,
.methods = gen_type_methods,
};
mp_obj_t mp_obj_new_gen_instance(const byte *bytecode, uint n_state, int n_args, const mp_obj_t *args) {
mp_obj_gen_instance_t *o = m_new_obj_var(mp_obj_gen_instance_t, mp_obj_t, n_state);
o->base.type = &gen_instance_type;
o->code_info = bytecode;
o->ip = bytecode;
o->sp = &o->state[0] - 1; // sp points to top of stack, which starts off 1 below the state
o->n_state = n_state;
// copy args to end of state array, in reverse (that's how mp_execute_byte_code_2 needs it)
for (int i = 0; i < n_args; i++) {
o->state[n_state - 1 - i] = args[i];
}
// TODO
// prelude for making cells (closed over variables)
// for now we just make sure there are no cells variables
// need to work out how to implement closed over variables in generators
// get code info size
machine_uint_t code_info_size = bytecode[0] | (bytecode[1] << 8) | (bytecode[2] << 16) | (bytecode[3] << 24);
o->ip += code_info_size;
assert(o->ip[0] == 0);
o->ip += 1;
return o;
}