Support conversion of structured objects to NP

lab/generic.py

@@ -831,13 +831,13 @@ def argsort(a, axis=-1, descending=False):
     """
 
 
-add_conversion_method(Number, NPNumeric, np.array)
-add_conversion_method(AGNumeric, NPNumeric,
-                      lambda x: convert(x._value, NPNumeric))
-add_conversion_method(TFNumeric, NPNumeric, lambda x: x.numpy())
-add_conversion_method(TorchNumeric, NPNumeric, lambda x: x.detach().numpy())
+NPOrNum = {NPNumeric, Number}  #: Type NumPy numeric or number.
+add_conversion_method(AGNumeric, NPOrNum, lambda x: x._value)
+add_conversion_method(TFNumeric, NPOrNum, lambda x: x.numpy())
+add_conversion_method(TorchNumeric, NPOrNum, lambda x: x.detach().numpy())
 
 
+@dispatch(object)
 def to_numpy(a):
     """Convert an object to NumPy.
 
@@ -847,4 +847,24 @@ def to_numpy(a):
     Returns:
         `np.ndarray`: `a` as NumPy.
     """
-    return convert(a, NPNumeric)
+    return convert(a, NPOrNum)
+
+
+@dispatch([object])
+def to_numpy(*elements):
+    return to_numpy(elements)
+
+
+@dispatch(list)
+def to_numpy(a):
+    return [to_numpy(x) for x in a]
+
+
+@dispatch(tuple)
+def to_numpy(a):
+    return tuple(to_numpy(x) for x in a)
+
+
+@dispatch(dict)
+def to_numpy(a):
+    return {k: to_numpy(v) for k, v in a.items()}

setup.cfg

@@ -1,6 +1,6 @@
 [metadata]
 name = backends
-version = 0.3.1
+version = 0.3.2
 author = Wessel Bruinsma
 author_email = wessel.p.bruinsma@gmail.com
 description = A generic interface for linear algebra backends

tests/test_generic.py

@@ -277,3 +277,22 @@ def test_argsort():
 def test_to_numpy():
     check_function(B.to_numpy, (Tensor(),))
     check_function(B.to_numpy, (Tensor(4),))
+
+
+def test_to_numpy_multiple_objects():
+    assert B.to_numpy(tf.constant(1), tf.constant(1)) == (1, 1)
+
+
+def test_to_numpy_list():
+    x = B.to_numpy([tf.constant(1)])
+    assert isinstance(x[0], (B.Number, B.NPNumeric))
+
+
+def test_to_numpy_tuple():
+    x = B.to_numpy((tf.constant(1),))
+    assert isinstance(x[0], (B.Number, B.NPNumeric))
+
+
+def test_to_numpy_dict():
+    x = B.to_numpy({'a': tf.constant(1)})
+    assert isinstance(x['a'], (B.Number, B.NPNumeric))