Allow object indices for typed memoryviews

Cython/Compiler/ExprNodes.py

@@ -2339,6 +2339,7 @@ class IndexNode(ExprNode):
     # Whether we are indexing or slicing a memoryviewslice
     memslice_index = False
     memslice_slice = False
+    warned_untyped_idx = False
 
     def __init__(self, pos, index, *args, **kw):
         ExprNode.__init__(self, pos, index=index, *args, **kw)
@@ -2542,6 +2543,11 @@ class IndexNode(ExprNode):
                             setattr(index, attr, value)
                             new_indices.append(value)
 
+                elif index.type.is_int or index.type.is_pyobject:
+                    if index.type.is_pyobject and not self.warned_untyped_idx:
+                        warning(index.pos, "Index should be typed for more "
+                                           "efficient access", level=2)
+                        IndexNode.warned_untyped_idx = True
                 elif index.type.is_int:
                     self.memslice_index = True
                     index = index.coerce_to(index_type, env)

tests/run/memslice.pyx

@@ -8,8 +8,6 @@ cimport cython
 from cython cimport view
 from cython.parallel cimport prange
 
-print cython.array
-
 import sys
 import re
 
@@ -1457,3 +1455,21 @@ def test_memslice_prange(arg):
         for j in range(src.shape[1]):
             for k in range(src.shape[2]):
                 assert src[i, j, k] == dst[i, j, k], (src[i, j, k] == dst[i, j, k])
+
+@testcase
+def test_object_indices():
+    """
+    >>> test_object_indices()
+    0
+    1
+    2
+    """
+    cdef int array[3]
+    cdef int[:] myslice = array
+    cdef int j
+
+    for i in range(3):
+        myslice[i] = i
+
+    for j in range(3):
+        print myslice[j]