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py: Add basic implementation of hasattr() function.
1 parent a086315 commit ff30666

5 files changed

Lines changed: 47 additions & 0 deletions

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‎py/builtin.c‎

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@@ -462,6 +462,21 @@ STATIC mp_obj_t mp_builtin_getattr(uint n_args, const mp_obj_t *args) {
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MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mp_builtin_getattr_obj, 2, 3, mp_builtin_getattr);
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STATIC mp_obj_t mp_builtin_hasattr(mp_obj_t object_in, mp_obj_t attr_in) {
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assert(MP_OBJ_IS_QSTR(attr_in));
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mp_obj_t dest[2];
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// TODO: https://docs.python.org/3.3/library/functions.html?highlight=hasattr#hasattr
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// explicitly says "This is implemented by calling getattr(object, name) and seeing
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// whether it raises an AttributeError or not.", so we should explicitly wrap this
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// in nlr_push and handle exception.
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mp_load_method_maybe(object_in, MP_OBJ_QSTR_VALUE(attr_in), dest);
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return MP_BOOL(dest[0] != MP_OBJ_NULL);
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}
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MP_DEFINE_CONST_FUN_OBJ_2(mp_builtin_hasattr_obj, mp_builtin_hasattr);
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// These two are defined in terms of MicroPython API functions right away
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MP_DEFINE_CONST_FUN_OBJ_0(mp_builtin_globals_obj, mp_globals_get);
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MP_DEFINE_CONST_FUN_OBJ_0(mp_builtin_locals_obj, mp_locals_get);

‎py/builtin.h‎

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@@ -41,6 +41,7 @@ MP_DECLARE_CONST_FUN_OBJ(mp_builtin_eval_obj);
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MP_DECLARE_CONST_FUN_OBJ(mp_builtin_exec_obj);
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MP_DECLARE_CONST_FUN_OBJ(mp_builtin_getattr_obj);
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MP_DECLARE_CONST_FUN_OBJ(mp_builtin_globals_obj);
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MP_DECLARE_CONST_FUN_OBJ(mp_builtin_hasattr_obj);
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MP_DECLARE_CONST_FUN_OBJ(mp_builtin_hash_obj);
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MP_DECLARE_CONST_FUN_OBJ(mp_builtin_hex_obj);
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MP_DECLARE_CONST_FUN_OBJ(mp_builtin_id_obj);

‎py/builtintables.c‎

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@@ -90,6 +90,7 @@ STATIC const mp_map_elem_t mp_builtin_object_table[] = {
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{ MP_OBJ_NEW_QSTR(MP_QSTR_exec), (mp_obj_t)&mp_builtin_exec_obj },
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{ MP_OBJ_NEW_QSTR(MP_QSTR_getattr), (mp_obj_t)&mp_builtin_getattr_obj },
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{ MP_OBJ_NEW_QSTR(MP_QSTR_globals), (mp_obj_t)&mp_builtin_globals_obj },
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{ MP_OBJ_NEW_QSTR(MP_QSTR_hasattr), (mp_obj_t)&mp_builtin_hasattr_obj },
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{ MP_OBJ_NEW_QSTR(MP_QSTR_hash), (mp_obj_t)&mp_builtin_hash_obj },
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{ MP_OBJ_NEW_QSTR(MP_QSTR_hex), (mp_obj_t)&mp_builtin_hex_obj },
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{ MP_OBJ_NEW_QSTR(MP_QSTR_id), (mp_obj_t)&mp_builtin_id_obj },

‎py/qstrdefs.h‎

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Original file line numberDiff line numberDiff line change
@@ -142,6 +142,7 @@ Q(float)
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Q(from_bytes)
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Q(getattr)
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Q(globals)
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Q(hasattr)
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Q(hash)
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Q(hex)
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Q(%#x)

‎tests/basics/hasattr1.py‎

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@@ -0,0 +1,29 @@
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class A:
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var = 132
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def __init__(self):
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self.var2 = 34
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def meth(self, i):
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return 42 + i
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a = A()
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print(hasattr(a, "var"))
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print(hasattr(a, "var2"))
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print(hasattr(a, "meth"))
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print(hasattr(a, "_none_such"))
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print(hasattr(list, "foo"))
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class C:
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def __getattr__(self, attr):
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if attr == "exists":
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return attr
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raise AttributeError
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c = C()
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print(hasattr(c, "exists"))
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# TODO
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#print(hasattr(c, "doesnt_exist"))

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