added filter()
diff --git a/py/mpqstrraw.h b/py/mpqstrraw.h
index bbca1bb..f6b4444 100644
--- a/py/mpqstrraw.h
+++ b/py/mpqstrraw.h
@@ -42,6 +42,7 @@
Q(dict)
Q(divmod)
Q(enumerate)
+Q(filter)
Q(float)
Q(hash)
Q(int)
diff --git a/py/obj.h b/py/obj.h
index 7779c47..c218286 100644
--- a/py/obj.h
+++ b/py/obj.h
@@ -300,6 +300,9 @@
// enumerate
extern const mp_obj_type_t enumerate_type;
+// filter
+extern const mp_obj_type_t filter_type;
+
// dict
extern const mp_obj_type_t dict_type;
uint mp_obj_dict_len(mp_obj_t self_in);
diff --git a/py/objfilter.c b/py/objfilter.c
new file mode 100644
index 0000000..6696ffe
--- /dev/null
+++ b/py/objfilter.c
@@ -0,0 +1,53 @@
+#include <stdlib.h>
+#include <assert.h>
+
+#include "misc.h"
+#include "mpconfig.h"
+#include "obj.h"
+#include "runtime.h"
+
+typedef struct _mp_obj_filter_t {
+ mp_obj_base_t base;
+ mp_obj_t fun;
+ mp_obj_t iter;
+} mp_obj_filter_t;
+
+static mp_obj_t filter_make_new(mp_obj_t type_in, int n_args, const mp_obj_t *args) {
+ /* NOTE: args are backwards */
+ mp_obj_filter_t *o = m_new_obj(mp_obj_filter_t);
+ assert(n_args == 2);
+ o->base.type = &filter_type;
+ o->fun = args[1];
+ o->iter = rt_getiter(args[0]);
+ return o;
+}
+
+static mp_obj_t filter_getiter(mp_obj_t self_in) {
+ return self_in;
+}
+
+static mp_obj_t filter_iternext(mp_obj_t self_in) {
+ assert(MP_OBJ_IS_TYPE(self_in, &filter_type));
+ mp_obj_filter_t *self = self_in;
+ mp_obj_t next;
+ while ((next = rt_iternext(self->iter)) != mp_const_stop_iteration) {
+ mp_obj_t val;
+ if (self->fun != mp_const_none) {
+ val = rt_call_function_n(self->fun, 1, &next);
+ } else {
+ val = next;
+ }
+ if (rt_is_true(val)) {
+ return next;
+ }
+ }
+ return mp_const_stop_iteration;
+}
+
+const mp_obj_type_t filter_type = {
+ { &mp_const_type },
+ "filter",
+ .make_new = filter_make_new,
+ .getiter = filter_getiter,
+ .iternext = filter_iternext,
+};
diff --git a/py/py.mk b/py/py.mk
index ba26fc0..daf2f59 100644
--- a/py/py.mk
+++ b/py/py.mk
@@ -79,6 +79,7 @@
objdict.o \
objenumerate.o \
objexcept.o \
+ objfilter.o \
objfloat.o \
objfun.o \
objgenerator.o \
diff --git a/py/runtime.c b/py/runtime.c
index c5292dc..04c098d 100644
--- a/py/runtime.c
+++ b/py/runtime.c
@@ -106,6 +106,7 @@
#endif
mp_map_add_qstr(&map_builtins, MP_QSTR_dict, (mp_obj_t)&dict_type);
mp_map_add_qstr(&map_builtins, MP_QSTR_enumerate, (mp_obj_t)&enumerate_type);
+ mp_map_add_qstr(&map_builtins, MP_QSTR_filter, (mp_obj_t)&filter_type);
#if MICROPY_ENABLE_FLOAT
mp_map_add_qstr(&map_builtins, MP_QSTR_float, (mp_obj_t)&float_type);
#endif
diff --git a/tests/basics/tests/filter.py b/tests/basics/tests/filter.py
new file mode 100644
index 0000000..5883e3d
--- /dev/null
+++ b/tests/basics/tests/filter.py
@@ -0,0 +1,2 @@
+print(list(filter(lambda x: x & 1, range(-3, 4))))
+print(list(filter(None, range(-3, 4))))