webassembly/objjsproxy: Implement proxying of JS iterable protocol.

This allows Python to iterate over JavaScript objects that provide
Symbol.iterator.

Signed-off-by: Damien George <damien@micropython.org>
This commit is contained in:
Damien George
2024-06-17 23:32:09 +10:00
parent 2b0e64beaf
commit a053e63914
3 changed files with 36 additions and 15 deletions

View File

@@ -153,14 +153,21 @@ EM_JS(void, js_reflect_construct, (int f_ref, uint32_t n_args, uint32_t * args,
proxy_convert_js_to_mp_obj_jsside(ret, out); proxy_convert_js_to_mp_obj_jsside(ret, out);
}); });
EM_JS(int, js_get_len, (int f_ref), { EM_JS(void, js_get_iter, (int f_ref, uint32_t * out), {
return proxy_js_ref[f_ref].length; const f = proxy_js_ref[f_ref];
const ret = f[Symbol.iterator]();
proxy_convert_js_to_mp_obj_jsside(ret, out);
}); });
EM_JS(void, js_subscr_int, (int f_ref, int idx, uint32_t * out), { EM_JS(bool, js_iter_next, (int f_ref, uint32_t * out), {
const f = proxy_js_ref[f_ref]; const f = proxy_js_ref[f_ref];
const ret = f[idx]; const ret = f.next();
proxy_convert_js_to_mp_obj_jsside(ret, out); if (ret.done) {
return false;
} else {
proxy_convert_js_to_mp_obj_jsside(ret.value, out);
return true;
}
}); });
EM_JS(void, js_subscr_load, (int f_ref, uint32_t * index_ref, uint32_t * out), { EM_JS(void, js_subscr_load, (int f_ref, uint32_t * index_ref, uint32_t * out), {
@@ -320,17 +327,13 @@ void mp_obj_jsproxy_attr(mp_obj_t self_in, qstr attr, mp_obj_t *dest) {
typedef struct _jsproxy_it_t { typedef struct _jsproxy_it_t {
mp_obj_base_t base; mp_obj_base_t base;
mp_fun_1_t iternext; mp_fun_1_t iternext;
mp_obj_jsproxy_t *obj; mp_obj_jsproxy_t *iter;
uint16_t cur;
uint16_t len;
} jsproxy_it_t; } jsproxy_it_t;
static mp_obj_t jsproxy_it_iternext(mp_obj_t self_in) { static mp_obj_t jsproxy_it_iternext(mp_obj_t self_in) {
jsproxy_it_t *self = MP_OBJ_TO_PTR(self_in); jsproxy_it_t *self = MP_OBJ_TO_PTR(self_in);
if (self->cur < self->len) { uint32_t out[3];
uint32_t out[3]; if (js_iter_next(self->iter->ref, out)) {
js_subscr_int(self->obj->ref, self->cur, out);
self->cur += 1;
return proxy_convert_js_to_mp_obj_cside(out); return proxy_convert_js_to_mp_obj_cside(out);
} else { } else {
return MP_OBJ_STOP_ITERATION; return MP_OBJ_STOP_ITERATION;
@@ -343,9 +346,9 @@ static mp_obj_t jsproxy_new_it(mp_obj_t self_in, mp_obj_iter_buf_t *iter_buf) {
jsproxy_it_t *o = (jsproxy_it_t *)iter_buf; jsproxy_it_t *o = (jsproxy_it_t *)iter_buf;
o->base.type = &mp_type_polymorph_iter; o->base.type = &mp_type_polymorph_iter;
o->iternext = jsproxy_it_iternext; o->iternext = jsproxy_it_iternext;
o->obj = self; uint32_t out[3];
o->cur = 0; js_get_iter(self->ref, out);
o->len = js_get_len(self->ref); o->iter = proxy_convert_js_to_mp_obj_cside(out);
return MP_OBJ_FROM_PTR(o); return MP_OBJ_FROM_PTR(o);
} }

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@@ -0,0 +1,14 @@
// Test accessing JavaScript iterables (objects with Symbol.iterator) from Python.
const mp = await (await import(process.argv[2])).loadMicroPython();
mp.runPython(`
import js
for v in js.Set.new([1, 2]):
print(v)
url_search_params = js.URLSearchParams.new("one=1&two=2")
for key in url_search_params.keys():
print(key, list(url_search_params.getAll(key)))
`);

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@@ -0,0 +1,4 @@
1
2
one ['1']
two ['2']