BUG: fix where(cond, float_array, int)

This should be allowed by the spec: python int scalars can combine with float arrays.

Author: ev-br

array_api_strict/_helpers.py

@@ -31,7 +31,7 @@ def _maybe_normalize_py_scalars(x1, x2, dtype_category, func_name):
         x2 = x1._promote_scalar(x2)
     else:
         if x1.dtype not in _allowed_dtypes or x2.dtype not in _allowed_dtypes:
-            raise TypeError(f"Only {dtype_category} dtypes are allowed {func_name}. "
+            raise TypeError(f"Only {dtype_category} dtypes are allowed in {func_name}(...). "
                             f"Got {x1.dtype} and {x2.dtype}.")
     return x1, x2
 

array_api_strict/_searching_functions.py

@@ -3,6 +3,7 @@
 from ._array_object import Array
 from ._dtypes import _result_type, _real_numeric_dtypes, bool as _bool
 from ._flags import requires_data_dependent_shapes, requires_api_version, get_array_api_strict_flags
+from ._helpers import _maybe_normalize_py_scalars
 
 from typing import TYPE_CHECKING
 if TYPE_CHECKING:
@@ -101,18 +102,7 @@ def where(
     See its docstring for more information.
     """
     if get_array_api_strict_flags()['api_version'] > '2023.12':
-        num_scalars = 0
-
-        if isinstance(x1, (bool, float, complex, int)):
-            x1 = Array._new(np.asarray(x1), device=condition.device)
-            num_scalars += 1
-
-        if isinstance(x2, (bool, float, complex, int)):
-            x2 = Array._new(np.asarray(x2), device=condition.device)
-            num_scalars += 1
-
-        if num_scalars == 2:
-            raise ValueError("One of x1, x2 arguments must be an array.")
+        x1, x2 = _maybe_normalize_py_scalars(x1, x2, "all", "where")
 
     # Call result type here just to raise on disallowed type combinations
     _result_type(x1.dtype, x2.dtype)

array_api_strict/tests/test_searching_functions.py

@@ -20,5 +20,18 @@ def test_where_with_scalars():
     assert xp.all(x_where == expected)
 
     # The spec does not allow both x1 and x2 to be scalars
-    with pytest.raises(ValueError, match="One of"):
+    with pytest.raises(TypeError, match="Two scalars"):
         xp.where(x == 1, 42, 44)
+
+
+def test_where_mixed_dtypes():
+    # https://github.com/data-apis/array-api-strict/issues/131
+    x =  xp.asarray([1., 2.])
+    res = xp.where(x > 1.5, x, 0)
+    assert res.dtype == x.dtype
+    assert all(res == xp.asarray([0., 2.]))
+
+    # retry with boolean x1, x2
+    c = x > 1.5
+    res = xp.where(c, False, c)
+    assert all(res == xp.asarray([False, False]))