From 13cfabd1b265d974e53e03d1d77eac7dc1d000e5 Mon Sep 17 00:00:00 2001
From: Paul Sokolovsky <pfalcon@users.sourceforge.net>
Date: Sun, 2 Feb 2014 03:32:55 +0200
Subject: [PATCH] Implement slicing for lists.

---
 py/obj.h              |  1 +
 py/objlist.c          | 10 +++++++++-
 tests/basics/list1.py |  4 ++++
 3 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/py/obj.h b/py/obj.h
index 45430d4a1c..bed5103dbd 100644
--- a/py/obj.h
+++ b/py/obj.h
@@ -396,3 +396,4 @@ typedef struct _mp_obj_classmethod_t {
 // sequence helpers
 void mp_seq_multiply(const void *items, uint item_sz, uint len, uint times, void *dest);
 bool m_seq_get_fast_slice_indexes(machine_uint_t len, mp_obj_t slice, machine_uint_t *begin, machine_uint_t *end);
+#define m_seq_copy(dest, src, len, item_sz) memcpy(dest, src, len * sizeof(item_sz))
diff --git a/py/objlist.c b/py/objlist.c
index b28ca81279..f3db99a637 100644
--- a/py/objlist.c
+++ b/py/objlist.c
@@ -136,7 +136,15 @@ static mp_obj_t list_binary_op(int op, mp_obj_t lhs, mp_obj_t rhs) {
     switch (op) {
         case RT_BINARY_OP_SUBSCR:
         {
-            // list load
+#if MICROPY_ENABLE_SLICE
+            if (MP_OBJ_IS_TYPE(rhs, &slice_type)) {
+                machine_uint_t start, stop;
+                assert(m_seq_get_fast_slice_indexes(o->len, rhs, &start, &stop));
+                mp_obj_list_t *res = list_new(stop - start);
+                m_seq_copy(res->items, o->items + start, res->len, mp_obj_t);
+                return res;
+            }
+#endif
             uint index = mp_get_index(o->base.type, o->len, rhs);
             return o->items[index];
         }
diff --git a/tests/basics/list1.py b/tests/basics/list1.py
index 250a12b704..8dc3939dd6 100644
--- a/tests/basics/list1.py
+++ b/tests/basics/list1.py
@@ -16,3 +16,7 @@ print(x)
 
 x += [2, 1]
 print(x)
+
+print(x[1:])
+print(x[:-1])
+print(x[2:3])