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-rw-r--r--py/mpconfig.h6
-rw-r--r--py/obj.h5
-rw-r--r--py/objslice.c74
-rw-r--r--py/objstr.c28
-rw-r--r--py/vm.c14
-rw-r--r--stm/Makefile1
-rw-r--r--tests/basics/tests/slice-bstr1.py27
-rw-r--r--unix-cpy/Makefile1
-rw-r--r--unix/Makefile1
9 files changed, 154 insertions, 3 deletions
diff --git a/py/mpconfig.h b/py/mpconfig.h
index 44095bd10b..56495d9156 100644
--- a/py/mpconfig.h
+++ b/py/mpconfig.h
@@ -25,3 +25,9 @@
#ifndef MICROPY_MEM_STATS
#define MICROPY_MEM_STATS (1)
#endif
+
+// Whether to support slice object and correspondingly
+// slice subscript operators
+#ifndef MICROPY_ENABLE_SLICE
+#define MICROPY_ENABLE_SLICE (1)
+#endif
diff --git a/py/obj.h b/py/obj.h
index 7b4b0656f2..16c7c36dd1 100644
--- a/py/obj.h
+++ b/py/obj.h
@@ -144,6 +144,7 @@ mp_obj_t mp_obj_new_list(uint n, mp_obj_t *items);
mp_obj_t mp_obj_new_list_reverse(uint n, mp_obj_t *items);
mp_obj_t mp_obj_new_dict(int n_args);
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 self, mp_obj_t meth);
mp_obj_t mp_obj_new_class(struct _mp_map_t *class_locals);
mp_obj_t mp_obj_new_instance(mp_obj_t clas);
@@ -214,6 +215,10 @@ mp_obj_t mp_obj_dict_store(mp_obj_t self_in, mp_obj_t key, mp_obj_t value);
// set
void mp_obj_set_store(mp_obj_t self_in, mp_obj_t item);
+// slice
+extern const mp_obj_type_t slice_type;
+void mp_obj_slice_get(mp_obj_t self_in, machine_int_t *start, machine_int_t *stop, machine_int_t *step);
+
// functions
typedef struct _mp_obj_fun_native_t { // need this so we can define const objects (to go in ROM)
mp_obj_base_t base;
diff --git a/py/objslice.c b/py/objslice.c
new file mode 100644
index 0000000000..03607e4c3e
--- /dev/null
+++ b/py/objslice.c
@@ -0,0 +1,74 @@
+#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 "runtime0.h"
+
+#if MICROPY_ENABLE_SLICE
+
+// TODO: This implements only variant of slice with 2 integer args only.
+// CPython supports 3rd arg (step), plus args can be arbitrary Python objects.
+typedef struct _mp_obj_slice_t {
+ mp_obj_base_t base;
+ machine_int_t start;
+ machine_int_t stop;
+} mp_obj_slice_t;
+
+void slice_print(void (*print)(void *env, const char *fmt, ...), void *env, mp_obj_t o_in) {
+ mp_obj_slice_t *o = o_in;
+ print(env, "slice(" INT_FMT ", " INT_FMT ")", o->start, o->stop);
+}
+
+const mp_obj_type_t slice_type = {
+ { &mp_const_type },
+ "slice",
+ slice_print,
+ NULL, // call_n
+ NULL, // unary_op
+ NULL, // binary_op
+ NULL, // getiter
+ NULL, // iternext
+ { { NULL, NULL }, }, // method list
+};
+
+// TODO: Make sure to handle "empty" values, which are signified by None in CPython
+mp_obj_t mp_obj_new_slice(mp_obj_t ostart, mp_obj_t ostop, mp_obj_t ostep) {
+ assert(ostep == NULL);
+ machine_int_t start = 0, stop = 0;
+ if (ostart != mp_const_none) {
+ start = mp_obj_get_int(ostart);
+ }
+ if (ostop != mp_const_none) {
+ stop = mp_obj_get_int(ostop);
+ if (stop == 0) {
+ // [x:0] is a special case - in our slice object, stop = 0 means
+ // "end of sequence". Fortunately, [x:0] is an empty seqence for
+ // any x (including negative). [x:x] is also always empty sequence.
+ // but x also can be 0. But note that b""[x:x] is b"" for any x (i.e.
+ // no IndexError, at least in Python 3.3.3). So, we just use -1's to
+ // signify that. -1 is catchy "special" number in case someone will
+ // try to print [x:0] slice ever.
+ start = stop = -1;
+ }
+ }
+ mp_obj_slice_t *o = m_new(mp_obj_slice_t, 1);
+ o->base.type = &slice_type;
+ o->start = start;
+ o->stop = stop;
+ return (mp_obj_t)o;
+}
+
+void mp_obj_slice_get(mp_obj_t self_in, machine_int_t *start, machine_int_t *stop, machine_int_t *step) {
+ assert(MP_OBJ_IS_TYPE(self_in, &slice_type));
+ mp_obj_slice_t *self = self_in;
+ *start = self->start;
+ *stop = self->stop;
+ *step = 1;
+}
+
+#endif
diff --git a/py/objstr.c b/py/objstr.c
index 48abf4951d..6a0721d45f 100644
--- a/py/objstr.c
+++ b/py/objstr.c
@@ -27,9 +27,31 @@ mp_obj_t str_binary_op(int op, mp_obj_t lhs_in, mp_obj_t rhs_in) {
const char *lhs_str = qstr_str(lhs->qstr);
switch (op) {
case RT_BINARY_OP_SUBSCR:
- // string access
- // XXX a massive hack!
- return mp_obj_new_int(lhs_str[mp_obj_get_int(rhs_in)]);
+ // TODO: need predicate to check for int-like type (bools are such for example)
+ // ["no", "yes"][1 == 2] is common idiom
+ if (MP_OBJ_IS_SMALL_INT(rhs_in)) {
+ // TODO: This implements byte string access for single index so far
+ // TODO: Handle negative indexes.
+ return mp_obj_new_int(lhs_str[mp_obj_get_int(rhs_in)]);
+#if MICROPY_ENABLE_SLICE
+ } else if (MP_OBJ_IS_TYPE(rhs_in, &slice_type)) {
+ int start, stop, step;
+ mp_obj_slice_get(rhs_in, &start, &stop, &step);
+ assert(step == 1);
+ int len = strlen(lhs_str);
+ if (start < 0) {
+ start = len + start;
+ }
+ if (stop <= 0) {
+ stop = len + stop;
+ }
+ return mp_obj_new_str(qstr_from_strn_copy(lhs_str + start, stop - start));
+#endif
+ } else {
+ // Message doesn't match CPython, but we don't have so much bytes as they
+ // to spend them on verbose wording
+ nlr_jump(mp_obj_new_exception_msg(rt_q_TypeError, "index must be int"));
+ }
case RT_BINARY_OP_ADD:
case RT_BINARY_OP_INPLACE_ADD:
diff --git a/py/vm.c b/py/vm.c
index c549e2b490..382780640b 100644
--- a/py/vm.c
+++ b/py/vm.c
@@ -410,6 +410,20 @@ bool mp_execute_byte_code_2(const byte **ip_in_out, mp_obj_t *fastn, mp_obj_t **
sp++;
break;
+#if MICROPY_ENABLE_SLICE
+ case MP_BC_BUILD_SLICE:
+ DECODE_UINT;
+ if (unum == 2) {
+ obj2 = POP();
+ obj1 = TOP();
+ SET_TOP(mp_obj_new_slice(obj1, obj2, NULL));
+ } else {
+ printf("3-argument slice is not supported\n");
+ assert(0);
+ }
+ break;
+#endif
+
case MP_BC_UNPACK_SEQUENCE:
DECODE_UINT;
rt_unpack_sequence(sp[0], unum, sp - unum + 1);
diff --git a/stm/Makefile b/stm/Makefile
index d6c77e2bd7..e84e21eae2 100644
--- a/stm/Makefile
+++ b/stm/Makefile
@@ -78,6 +78,7 @@ PY_O = \
objnone.o \
objrange.o \
objset.o \
+ objslice.o \
objstr.o \
objtuple.o \
objtype.o \
diff --git a/tests/basics/tests/slice-bstr1.py b/tests/basics/tests/slice-bstr1.py
new file mode 100644
index 0000000000..8b492b35cc
--- /dev/null
+++ b/tests/basics/tests/slice-bstr1.py
@@ -0,0 +1,27 @@
+b"123"[0:1]
+
+b"123"[0:2]
+
+b"123"[:1]
+
+b"123"[1:]
+
+# Idiom for copying sequence
+b"123"[:]
+
+b"123"[:-1]
+
+# Weird cases
+b"123"[0:0]
+b"123"[1:0]
+b"123"[1:1]
+b"123"[-1:-1]
+b"123"[-3:]
+b"123"[-3:3]
+b"123"[0:]
+b"123"[:0]
+b"123"[:-3]
+b"123"[:-4]
+# No IndexError!
+b""[1:1]
+b""[-1:-1]
diff --git a/unix-cpy/Makefile b/unix-cpy/Makefile
index 48c3179460..7fee3438fb 100644
--- a/unix-cpy/Makefile
+++ b/unix-cpy/Makefile
@@ -43,6 +43,7 @@ PY_O = \
objnone.o \
objrange.o \
objset.o \
+ objslice.o \
objstr.o \
objtuple.o \
objtype.o \
diff --git a/unix/Makefile b/unix/Makefile
index fd5b6b43e0..38d6ba8e15 100644
--- a/unix/Makefile
+++ b/unix/Makefile
@@ -50,6 +50,7 @@ PY_O = \
objnone.o \
objrange.o \
objset.o \
+ objslice.o \
objstr.o \
objtuple.o \
objtype.o \
generated by cgit v1.2.3 (git 2.39.1) at 2025-05-12 15:25:04 +0000