implement recursive carray copying (arrays of arrays)

Cython/Compiler/ExprNodes.py

@@ -4065,13 +4065,7 @@ class SliceIndexNode(ExprNode):
                     has_c_start, has_c_stop,
                     bool(code.globalstate.directives['wraparound'])))
         else:
-            start_offset = ''
-            if self.start:
-                start_offset = self.start_code()
-                if start_offset == '0':
-                    start_offset = ''
-                else:
-                    start_offset += '+'
+            start_offset = self.start_code() if self.start else '0'
             if rhs.type.is_array:
                 array_length = rhs.type.size
                 self.generate_slice_guard_code(code, array_length)
@@ -4080,10 +4074,31 @@ class SliceIndexNode(ExprNode):
                       "Slice assignments from pointers are not yet supported.")
                 # FIXME: fix the array size according to start/stop
                 array_length = self.base.type.size
-            for i in range(array_length):
-                code.putln("%s[%s%s] = %s[%d];" % (
-                        self.base.result(), start_offset, i,
-                        rhs.result(), i))
+
+            def copy_carray(dst, src, item_type, start, count, depth):
+                var_name = Naming.quick_temp_cname
+                if depth:
+                    var_name += str(depth)
+                dst_item, src_item = '{dst}[{i}+{start}] = {src}[{i}]'.format(
+                    src=src,
+                    dst=dst,
+                    start=start,
+                    i=var_name
+                ).split(' = ')
+
+                code.putln('{')
+                code.putln('Py_ssize_t %s;' % var_name)
+                code.put('for ({i}=0; {i} < {count}; {i}++) '.format(
+                    i=var_name,
+                    count=count))
+                if item_type.is_array:
+                    copy_carray(dst_item, src_item, item_type.base_type, 0, item_type.size, depth + 1)
+                else:
+                    code.putln('%s = %s;' % (dst_item, src_item))
+                code.putln('}')
+
+            copy_carray(self.base.result(), rhs.result(), rhs.type.base_type,
+                        start_offset, array_length, 0)
         self.generate_subexpr_disposal_code(code)
         self.free_subexpr_temps(code)
         rhs.generate_disposal_code(code)

tests/run/carray_coercion.pyx

@@ -115,6 +115,62 @@ def to_int_array(x):
     return v[0], v[1], v[2]
 
 
+def to_int_array_array(x):
+    """
+    >>> to_int_array_array([[1, 2, 3], [4, 5, 6]])
+    (1, 2, 3, 4, 5, 6)
+    >>> to_int_array_array(iter([[1, 2, 3], [4, 5, 6]]))
+    (1, 2, 3, 4, 5, 6)
+
+    >>> to_int_array_array([[1, 2, 3]])
+    Traceback (most recent call last):
+    IndexError: not enough values found during array assignment, expected 2, got 1
+    >>> to_int_array_array(iter([[1, 2, 3]]))
+    Traceback (most recent call last):
+    IndexError: not enough values found during array assignment, expected 2, got 1
+
+    >>> to_int_array_array([[1, 2, 3], [4, 5]])
+    Traceback (most recent call last):
+    IndexError: not enough values found during array assignment, expected 3, got 2
+    >>> to_int_array_array(iter([[1, 2, 3], [4, 5]]))
+    Traceback (most recent call last):
+    IndexError: not enough values found during array assignment, expected 3, got 2
+
+    >>> to_int_array_array([[1, 2, 3, 4], [5, 6, 7]])
+    Traceback (most recent call last):
+    IndexError: too many values found during array assignment, expected 3
+    >>> to_int_array_array(iter([[1, 2, 3, 4], [5, 6, 7]]))
+    Traceback (most recent call last):
+    IndexError: too many values found during array assignment, expected 3
+    """
+    cdef int[2][3] v = x
+    return v[0][0], v[0][1], v[0][2], v[1][0], v[1][1], v[1][2]
+
+
+'''
+# FIXME: this isn't currently allowed
+cdef enum:
+    SIZE_A = 2
+    SIZE_B = 3
+
+def to_int_array_array_enumsize(x):
+    """
+    >>> to_int_array_array([[1, 2, 3], [4, 5, 6]])
+    (1, 2, 3, 4, 5, 6)
+    >>> to_int_array_array(iter([[1, 2, 3], [4, 5, 6]]))
+    (1, 2, 3, 4, 5, 6)
+    >>> to_int_array([1, 2])
+    Traceback (most recent call last):
+    IndexError: not enough values found during array assignment, expected 3, got 2
+    >>> to_int_array([1, 2, 3, 4])
+    Traceback (most recent call last):
+    IndexError: too many values found during array assignment, expected 3
+    """
+    cdef int[SIZE_A][SIZE_B] v = x
+    return v[0][0], v[0][1], v[0][2], v[1][0], v[1][1], v[1][2]
+'''
+
+
 def to_int_array_slice(x):
     """
     >>> to_int_array_slice([1, 2, 3])
@@ -175,3 +231,18 @@ def to_struct_array(x):
     assert w[1].y == v[1].y
 
     return v[0], w[1]
+
+
+def to_struct_array_array(x):
+    """
+    >>> (a1, a2, a3), (b1, b2, b3) = to_struct_array_array([
+    ...     ({'x': 11, 'y': 12}, {'x': 13, 'y': 14}, {'x': 15, 'y': 16}),
+    ...     ({'x': 21, 'y': 22}, {'x': 23, 'y': 24}, {'x': 25, 'y': 26}),
+    ... ])
+    >>> a1['x'], a1['y']
+    (11, 12.0)
+    >>> b3['x'], b3['y']
+    (25, 26.0)
+    """
+    cdef MyStructType[2][3] v = x
+    return v[0], v[1]