re-add sorting

Author: ev-br

array_api_compat/torch/_aliases.py

@@ -140,10 +140,18 @@ def result_type(*arrays_and_dtypes: Union[array, Dtype, bool, int, float, comple
         return _result_type(x, y)
 
     else:
-        if _builtin_all(isinstance(x, _py_scalars) for x in arrays_and_dtypes):
+        # sort scalars so that they are treated last
+        scalars, others = [], []
+        for x in arrays_and_dtypes:
+            if isinstance(x, _py_scalars):
+                scalars.append(x)
+            else:
+                others.append(x)
+        if not others:
             raise ValueError("At least one array or dtype must be provided")
 
-        return _reduce(_result_type, arrays_and_dtypes)
+        # combine left-to-right
+        return _reduce(_result_type, others + scalars)
 
 
 def _result_type(x, y):

tests/test_torch.py

@@ -1,5 +1,7 @@
 """Test "unspecified" behavior which we cannot easily test in the Array API test suite.
 """
+import itertools
+
 import pytest
 import torch
 
@@ -51,7 +53,10 @@ def test_two_args(self):
     def test_multi_arg(self):
         torch.set_default_dtype(torch.float32)
 
-        args = [1, 2, 3j, xp.arange(3), 4, 5, 6]
+        args = [1., 5, 3, torch.asarray([3], dtype=torch.float16), 5, 6, 1.]
+        assert xp.result_type(*args) == torch.float16
+
+        args = [1, 2, 3j, xp.arange(3, dtype=xp.float32), 4, 5, 6]
         assert xp.result_type(*args) == xp.complex64
 
         args = [1, 2, 3j, xp.float64, 4, 5, 6]
@@ -60,5 +65,10 @@ def test_multi_arg(self):
         args = [1, 2, 3j, xp.float64, 4, xp.asarray(3, dtype=xp.int16), 5, 6, False]
         assert xp.result_type(*args) == xp.complex128
 
+        i64 = xp.ones(1, dtype=xp.int64)
+        f16 = xp.ones(1, dtype=xp.float16)
+        for i in itertools.permutations([i64, f16, 1.0, 1.0]):
+            assert xp.result_type(*i) == xp.float16, f"{i}"
+
         with pytest.raises(ValueError):
             xp.result_type(1, 2, 3, 4)