Support use of DType instance in UDF annotation (#5200)

py/server/deephaven/_udf.py

@@ -119,6 +119,11 @@ def _parse_type_no_nested(annotation: Any, p_param: _ParsedParam, t: Union[type,
     t = eval(t) if isinstance(t, str) else t
 
     p_param.orig_types.add(t)
+
+    # if the annotation is a DH DType instance, we'll use its numpy type
+    if isinstance(t, dtypes.DType):
+        t = t.np_type
+
     tc = _encode_param_type(t)
     if "[" in tc:
         p_param.has_array = True
@@ -157,6 +162,11 @@ def _parse_return_annotation(annotation: Any) -> _ParsedReturnAnnotation:
             t = annotation.__args__[0]
         elif annotation.__args__[0] == type(None):  # noqa: E721
             t = annotation.__args__[1]
+
+    # if the annotation is a DH DType instance, we'll use its numpy type
+    if isinstance(t, dtypes.DType):
+        t = t.np_type
+
     component_char = _component_np_dtype_char(t)
     if component_char:
         pra.encoded_type = "[" + component_char

py/server/deephaven/dtypes.py

@@ -412,6 +412,9 @@ def _component_np_dtype_char(t: type) -> Optional[str]:
     component_type = None
     if isinstance(t, _GenericAlias) and issubclass(t.__origin__, Sequence):
         component_type = t.__args__[0]
+        # if the component type is a DType, get its numpy type
+        if isinstance(component_type, DType):
+            component_type = component_type.np_type
 
     if not component_type:
         component_type = _np_ndarray_component_type(t)

py/server/tests/test_udf_return_java_values.py

@@ -293,6 +293,16 @@ def nbsin(x):
         t3 = empty_table(10).update(["X3 = nbsin(i)"])
         self.assertEqual(t3.columns[0].data_type, dtypes.double)
 
+    def test_java_instant_return(self):
+        from deephaven.time import to_j_instant
+
+        t = empty_table(10).update(["X1 = to_j_instant(`2021-01-01T00:00:00Z`)"])
+        self.assertEqual(t.columns[0].data_type, dtypes.Instant)
+
+        def udf() -> List[dtypes.Instant]:
+            return [to_j_instant("2021-01-01T00:00:00Z")]
+        t = empty_table(10).update(["X1 = udf()"])
+        self.assertEqual(t.columns[0].data_type, dtypes.instant_array)
 
 if __name__ == '__main__':
     unittest.main()