1 files changed, 130 insertions, 0 deletions
diff --git a/py/objgenerator.c b/py/objgenerator.c
new file mode 100644
index 0000000000..fdb642c1c4
--- /dev/null
+++ b/py/objgenerator.c
@@ -0,0 +1,130 @@
+#include <stdlib.h>
+#include <stdint.h>
+#include <string.h>
+#include <assert.h>
+
+#include "nlr.h"
+#include "misc.h"
+#include "mpconfig.h"
+#include "obj.h"
+#include "runtime.h"
+#include "bc.h"
+
+/******************************************************************************/
+/* generator wrapper                                                          */
+
+typedef struct _mp_obj_gen_wrap_t {
+    mp_obj_base_t base;
+    int n_state;
+    mp_obj_t *fun;
+} mp_obj_gen_wrap_t;
+
+// args are in reverse order in the array
+mp_obj_t gen_wrap_call_n(mp_obj_t self_in, int n_args, 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_2_args(rt_q_TypeError, "function takes %d positional arguments but %d were given", (const char*)(machine_int_t)bc_n_args, (const char*)(machine_int_t)n_args));
+    }
+    mp_obj_t *state = m_new(mp_obj_t, 1 + self->n_state);
+    // put function object at first slot in state (to keep u_gen_instance small)
+    state[0] = self_fun;
+    // init args
+    for (int i = 0; i < n_args; i++) {
+        state[1 + i] = args[n_args - 1 - i];
+    }
+    return mp_obj_new_gen_instance(state, bc_code, state + self->n_state);
+}
+
+const mp_obj_type_t gen_wrap_type = {
+    { &mp_const_type },
+    "generator",
+    NULL, // print
+    gen_wrap_call_n, // call_n
+    NULL, // unary_op
+    NULL, // binary_op
+    NULL, // getiter
+    NULL, // iternext
+    {{NULL, NULL},}, // method list
+};
+
+mp_obj_t mp_obj_new_gen_wrap(uint n_locals, uint n_cells, uint n_stack, mp_obj_t fun) {
+    mp_obj_gen_wrap_t *o = m_new_obj(mp_obj_gen_wrap_t);
+    o->base.type = &gen_wrap_type;
+    // we have at least 3 locals so the bc can write back fast[0,1,2] safely; should improve how this is done
+    o->n_state = ((n_locals + n_cells) < 3 ? 3 : (n_locals + n_cells)) + n_stack;
+    o->fun = fun;
+    return o;
+}
+
+/******************************************************************************/
+/* generator instance                                                         */
+
+typedef struct _mp_obj_gen_instance_t {
+    mp_obj_base_t base;
+    mp_obj_t *state;
+    const byte *ip;
+    mp_obj_t *sp;
+} mp_obj_gen_instance_t;
+
+void gen_instance_print(void (*print)(void *env, const char *fmt, ...), void *env, mp_obj_t self_in) {
+    print(env, "<generator object 'fun-name' at %p>", self_in);
+}
+
+mp_obj_t gen_instance_getiter(mp_obj_t self_in) {
+    return self_in;
+}
+
+mp_obj_t gen_instance_iternext(mp_obj_t self_in) {
+    mp_obj_gen_instance_t *self = self_in;
+    //mp_obj_base_t *fun = self->u_gen_instance.state[0];
+    //assert(fun->kind == O_FUN_BC);
+    bool yield = mp_execute_byte_code_2(&self->ip, &self->state[1], &self->sp);
+    if (yield) {
+        return *self->sp;
+    } else {
+        if (*self->sp == mp_const_none) {
+            return mp_const_stop_iteration;
+        } else {
+            // TODO return StopIteration with value *self->sp
+            return mp_const_stop_iteration;
+        }
+    }
+}
+
+const mp_obj_type_t gen_instance_type = {
+    { &mp_const_type },
+    "generator",
+    gen_instance_print, // print
+    NULL, // call_n
+    NULL, // unary_op
+    NULL, // binary_op
+    gen_instance_getiter, // getiter
+    gen_instance_iternext, // iternext
+    {{NULL, NULL},}, // method list
+};
+
+mp_obj_t mp_obj_new_gen_instance(mp_obj_t state, const byte *ip, mp_obj_t *sp) {
+    mp_obj_gen_instance_t *o = m_new_obj(mp_obj_gen_instance_t);
+    o->base.type = &gen_instance_type;
+    o->state = state;
+    o->ip = ip;
+    o->sp = sp;
+    return o;
+}
+
+mp_obj_t mp_obj_gen_instance_next(mp_obj_t self_in) {
+    mp_obj_t ret = rt_iternext(self_in);
+    if (ret == mp_const_stop_iteration) {
+        nlr_jump(mp_obj_new_exception(qstr_from_str_static("StopIteration")));
+    } else {
+        return ret;
+    }
+}
+
+MP_DEFINE_CONST_FUN_OBJ_1(mp_obj_gen_instance_next_obj, mp_obj_gen_instance_next);