py: Implement iterator support for object that has __getitem__.
Addresses Issue #203.
diff --git a/py/obj.h b/py/obj.h
index 68d9588..e122f5a 100644
--- a/py/obj.h
+++ b/py/obj.h
@@ -39,7 +39,7 @@
#define MP_OBJ_IS_SMALL_INT(o) ((((mp_small_int_t)(o)) & 1) != 0)
#define MP_OBJ_IS_QSTR(o) ((((mp_small_int_t)(o)) & 3) == 2)
#define MP_OBJ_IS_OBJ(o) ((((mp_small_int_t)(o)) & 3) == 0)
-#define MP_OBJ_IS_TYPE(o, t) (MP_OBJ_IS_OBJ(o) && (((mp_obj_base_t*)(o))->type == (t)))
+#define MP_OBJ_IS_TYPE(o, t) (MP_OBJ_IS_OBJ(o) && (((mp_obj_base_t*)(o))->type == (t))) // this does not work for checking a string, use below macro for that
#define MP_OBJ_IS_STR(o) (MP_OBJ_IS_QSTR(o) || MP_OBJ_IS_TYPE(o, &str_type))
#define MP_OBJ_SMALL_INT_VALUE(o) (((mp_small_int_t)(o)) >> 1)
@@ -231,6 +231,7 @@
mp_obj_t mp_obj_new_set(int n_args, mp_obj_t *items);
mp_obj_t mp_obj_new_slice(mp_obj_t start, mp_obj_t stop, mp_obj_t step);
mp_obj_t mp_obj_new_bound_meth(mp_obj_t meth, mp_obj_t self);
+mp_obj_t mp_obj_new_getitem_iter(mp_obj_t *args);
mp_obj_t mp_obj_new_module(qstr module_name);
mp_obj_type_t *mp_obj_get_type(mp_obj_t o_in);
diff --git a/py/objgetitemiter.c b/py/objgetitemiter.c
new file mode 100644
index 0000000..40ed1a1
--- /dev/null
+++ b/py/objgetitemiter.c
@@ -0,0 +1,53 @@
+#include <stdlib.h>
+#include <stdint.h>
+
+#include "nlr.h"
+#include "misc.h"
+#include "mpconfig.h"
+#include "qstr.h"
+#include "obj.h"
+#include "runtime.h"
+
+// this is a wrapper object that is turns something that has a __getitem__ method into an iterator
+
+typedef struct _mp_obj_getitem_iter_t {
+ mp_obj_base_t base;
+ mp_obj_t args[3];
+} mp_obj_getitem_iter_t;
+
+static mp_obj_t it_iternext(mp_obj_t self_in) {
+ mp_obj_getitem_iter_t *self = self_in;
+ nlr_buf_t nlr;
+ if (nlr_push(&nlr) == 0) {
+ // try to get next item
+ mp_obj_t value = rt_call_method_n_kw(1, 0, self->args);
+ self->args[2] = MP_OBJ_NEW_SMALL_INT(MP_OBJ_SMALL_INT_VALUE(self->args[2]) + 1);
+ nlr_pop();
+ return value;
+ } else {
+ // an exception was raised
+ if (MP_OBJ_IS_TYPE(nlr.ret_val, &exception_type) && mp_obj_exception_get_type(nlr.ret_val) == MP_QSTR_StopIteration) {
+ // return mp_const_stop_iteration instead of raising StopIteration
+ return mp_const_stop_iteration;
+ } else {
+ // re-raise exception
+ nlr_jump(nlr.ret_val);
+ }
+ }
+}
+
+static const mp_obj_type_t it_type = {
+ { &mp_const_type },
+ "iterator",
+ .iternext = it_iternext
+};
+
+// args are those returned from rt_load_method_maybe (ie either an attribute or a method)
+mp_obj_t mp_obj_new_getitem_iter(mp_obj_t *args) {
+ mp_obj_getitem_iter_t *o = m_new_obj(mp_obj_getitem_iter_t);
+ o->base.type = &it_type;
+ o->args[0] = args[0];
+ o->args[1] = args[1];
+ o->args[2] = MP_OBJ_NEW_SMALL_INT(0);
+ return o;
+}
diff --git a/py/objstr.c b/py/objstr.c
index 723eebd..3a4d69c 100644
--- a/py/objstr.c
+++ b/py/objstr.c
@@ -77,7 +77,7 @@
if (MP_OBJ_IS_SMALL_INT(rhs_in)) {
uint index = mp_get_index(mp_obj_get_type(lhs_in), lhs_len, rhs_in);
if (MP_OBJ_IS_TYPE(lhs_in, &bytes_type)) {
- return MP_OBJ_NEW_SMALL_INT(lhs_data[index]);
+ return MP_OBJ_NEW_SMALL_INT((mp_small_int_t)lhs_data[index]);
} else {
return mp_obj_new_str(lhs_data + index, 1, true);
}
@@ -549,7 +549,7 @@
mp_obj_str_it_t *self = self_in;
GET_STR_DATA_LEN(self->str, str, len);
if (self->cur < len) {
- mp_obj_t o_out = MP_OBJ_NEW_SMALL_INT(str[self->cur]);
+ mp_obj_t o_out = MP_OBJ_NEW_SMALL_INT((mp_small_int_t)str[self->cur]);
self->cur += 1;
return o_out;
} else {
diff --git a/py/objtype.c b/py/objtype.c
index 75755f4..afa34aa 100644
--- a/py/objtype.c
+++ b/py/objtype.c
@@ -117,8 +117,8 @@
}
// TODO somehow replace const char * with a qstr
-static const char *binary_op_method_name[] = {
- [RT_BINARY_OP_SUBSCR] = "__getitem__",
+static const qstr binary_op_method_name[] = {
+ [RT_BINARY_OP_SUBSCR] = MP_QSTR___getitem__,
/*
RT_BINARY_OP_OR,
RT_BINARY_OP_XOR,
@@ -126,8 +126,8 @@
RT_BINARY_OP_LSHIFT,
RT_BINARY_OP_RSHIFT,
*/
- [RT_BINARY_OP_ADD] = "__add__",
- [RT_BINARY_OP_SUBTRACT] = "__sub__",
+ [RT_BINARY_OP_ADD] = MP_QSTR___add__,
+ [RT_BINARY_OP_SUBTRACT] = MP_QSTR___sub__,
/*
RT_BINARY_OP_MULTIPLY,
RT_BINARY_OP_FLOOR_DIVIDE,
@@ -157,16 +157,16 @@
RT_COMPARE_OP_IS,
RT_COMPARE_OP_IS_NOT,
*/
- [RT_COMPARE_OP_EXCEPTION_MATCH] = "__not_implemented__",
+ [RT_COMPARE_OP_EXCEPTION_MATCH] = MP_QSTR_, // not implemented, used to make sure array has full size
};
static mp_obj_t class_binary_op(int op, mp_obj_t lhs_in, mp_obj_t rhs_in) {
mp_obj_class_t *lhs = lhs_in;
- const char *op_name = binary_op_method_name[op];
- if (op_name == NULL) {
+ qstr op_name = binary_op_method_name[op];
+ if (op_name == 0) {
return MP_OBJ_NULL;
}
- mp_obj_t member = mp_obj_class_lookup(lhs->base.type, QSTR_FROM_STR_STATIC(op_name));
+ mp_obj_t member = mp_obj_class_lookup(lhs->base.type, op_name);
if (member != MP_OBJ_NULL) {
return rt_call_function_2(member, lhs_in, rhs_in);
} else {
diff --git a/py/py.mk b/py/py.mk
index d4946e2..742e6e3 100644
--- a/py/py.mk
+++ b/py/py.mk
@@ -47,6 +47,7 @@
objfloat.o \
objfun.o \
objgenerator.o \
+ objgetitemiter.o \
objint.o \
objint_longlong.o \
objlist.o \
diff --git a/py/qstrdefs.h b/py/qstrdefs.h
index f2c4dfd..e76efaf 100644
--- a/py/qstrdefs.h
+++ b/py/qstrdefs.h
@@ -13,6 +13,10 @@
Q(__qualname__)
Q(__repl_print__)
+Q(__getitem__)
+Q(__add__)
+Q(__sub__)
+
Q(micropython)
Q(byte_code)
Q(native)
diff --git a/py/runtime.c b/py/runtime.c
index 3d56cc8..976d23a 100644
--- a/py/runtime.c
+++ b/py/runtime.c
@@ -87,7 +87,7 @@
// init loaded modules table
mp_map_init(&map_loaded_modules, 3);
- // built-in exceptions (TODO, make these proper classes)
+ // built-in exceptions (TODO, make these proper classes, and const if possible)
mp_map_add_qstr(&map_builtins, MP_QSTR_AttributeError, mp_obj_new_exception(MP_QSTR_AttributeError));
mp_map_add_qstr(&map_builtins, MP_QSTR_IndexError, mp_obj_new_exception(MP_QSTR_IndexError));
mp_map_add_qstr(&map_builtins, MP_QSTR_KeyError, mp_obj_new_exception(MP_QSTR_KeyError));
@@ -100,6 +100,7 @@
mp_map_add_qstr(&map_builtins, MP_QSTR_OverflowError, mp_obj_new_exception(MP_QSTR_OverflowError));
mp_map_add_qstr(&map_builtins, MP_QSTR_OSError, mp_obj_new_exception(MP_QSTR_OSError));
mp_map_add_qstr(&map_builtins, MP_QSTR_AssertionError, mp_obj_new_exception(MP_QSTR_AssertionError));
+ mp_map_add_qstr(&map_builtins, MP_QSTR_StopIteration, mp_obj_new_exception(MP_QSTR_StopIteration));
// built-in objects
mp_map_add_qstr(&map_builtins, MP_QSTR_Ellipsis, mp_const_ellipsis);
@@ -805,7 +806,7 @@
// use load_method
mp_obj_t dest[2];
rt_load_method(base, attr, dest);
- if (dest[1] == NULL) {
+ if (dest[1] == MP_OBJ_NULL) {
// load_method returned just a normal attribute
return dest[0];
} else {
@@ -814,9 +815,10 @@
}
}
-void rt_load_method(mp_obj_t base, qstr attr, mp_obj_t *dest) {
- DEBUG_OP_printf("load method %p.%s\n", base, qstr_str(attr));
-
+// no attribute found, returns: dest[0] == MP_OBJ_NULL, dest[1] == MP_OBJ_NULL
+// normal attribute found, returns: dest[0] == <attribute>, dest[1] == MP_OBJ_NULL
+// method attribute found, returns: dest[0] == <method>, dest[1] == <self>
+static void rt_load_method_maybe(mp_obj_t base, qstr attr, mp_obj_t *dest) {
// clear output to indicate no attribute/method found yet
dest[0] = MP_OBJ_NULL;
dest[1] = MP_OBJ_NULL;
@@ -830,7 +832,7 @@
}
// if nothing found yet, look for built-in and generic names
- if (dest[0] == NULL) {
+ if (dest[0] == MP_OBJ_NULL) {
if (attr == MP_QSTR___next__ && type->iternext != NULL) {
dest[0] = (mp_obj_t)&mp_builtin_next_obj;
dest[1] = base;
@@ -861,8 +863,14 @@
}
}
}
+}
- if (dest[0] == NULL) {
+void rt_load_method(mp_obj_t base, qstr attr, mp_obj_t *dest) {
+ DEBUG_OP_printf("load method %p.%s\n", base, qstr_str(attr));
+
+ rt_load_method_maybe(base, attr, dest);
+
+ if (dest[0] == MP_OBJ_NULL) {
// no attribute/method called attr
// following CPython, we give a more detailed error message for type objects
if (MP_OBJ_IS_TYPE(base, &mp_const_type)) {
@@ -910,7 +918,16 @@
if (type->getiter != NULL) {
return type->getiter(o_in);
} else {
- nlr_jump(mp_obj_new_exception_msg_varg(MP_QSTR_TypeError, "'%s' object is not iterable", type->name));
+ // check for __getitem__ method
+ mp_obj_t dest[2];
+ rt_load_method_maybe(o_in, qstr_from_str("__getitem__"), dest);
+ if (dest[0] != MP_OBJ_NULL) {
+ // __getitem__ exists, create an iterator
+ return mp_obj_new_getitem_iter(dest);
+ } else {
+ // object not iterable
+ nlr_jump(mp_obj_new_exception_msg_varg(MP_QSTR_TypeError, "'%s' object is not iterable", type->name));
+ }
}
}
diff --git a/tests/basics/getitem.py b/tests/basics/getitem.py
new file mode 100644
index 0000000..f39296a
--- /dev/null
+++ b/tests/basics/getitem.py
@@ -0,0 +1,22 @@
+# create a class that has a __getitem__ method
+class A:
+ def __getitem__(self, index):
+ print('getitem', index)
+ if index > 10:
+ raise StopIteration
+
+# test __getitem__
+A()[0]
+A()[1]
+
+# iterate using a for loop
+for i in A():
+ pass
+
+# iterate manually
+it = iter(A())
+try:
+ while True:
+ next(it)
+except StopIteration:
+ pass