Refine the statement

velox/docs/develop/scalar-functions.rst

@@ -580,10 +580,15 @@ The “rows” parameter specifies the set of rows in the incoming batch to
 process. This set may not include all the rows. By default, a vector function
 is assumed to have the default null behavior, e.g. null in any input produces
 a null result. In this case, the expression evaluation engine will exclude
-rows with nulls from the “rows” specified in the call to “apply”. If a
-function has a different behavior for null inputs, VectorFunctionMetadata's
-defaultNullBehavior must be set to false when it is registered. See the below
-"Registration" section.
+rows with nulls from the “rows” specified in the call to “apply”. If a function
+has a different behavior for null inputs, metadata flag must be provided with
+defaultNullBehavior set to false during registration. See the below "Registration"
+section.
+
+.. code-block:: c++
+
+    VectorFunctionMetadata metadata =
+      exec::VectorFunctionMetadataBuilder().defaultNullBehavior(false).build();
 
 In this case, the “rows” parameter will include rows with null inputs and the
 function will need to handle these. By default, the function can assume that
@@ -636,10 +641,15 @@ of the function arguments. These vectors are not necessarily flat and may be
 dictionary or constant encoded. However, a deterministic function that takes
 a single argument and has default null behavior is guaranteed to receive its
 only input as a flat or constant vector. By default, a function is assumed to
-be deterministic. If that’s not the case, VectorFunctionMetadata's deterministic
-must be set to false when such function is registered. See the below "Registration"
+be deterministic. If that’s not the case, metadata flag must be provided with
+deterministic set to false during registration. See the below "Registration"
 section.
 
+.. code-block:: c++
+
+    VectorFunctionMetadata metadata =
+      exec::VectorFunctionMetadataBuilder().deterministic(false).build();
+
 Note that :ref:`decoded-vector` can be used to get a flat vector-like interface to any
 vector. A helper class exec::DecodedArgs can be used to decode multiple arguments.
 
@@ -865,17 +875,9 @@ Use exec::registerVectorFunction to register a stateless vector function.
 
 exec::registerVectorFunction takes a name, a list of supported signatures
 and unique_ptr to an instance of the function. It is optional to provide
-metadata flag to set deterministic or defaultNullBehavior.
-
-.. code-block:: c++
-
-    auto metadata = exec::VectorFunctionMetadataBuilder()
-                      .deterministic(false)
-                      .defaultNullBehavior(false)
-                      .build();
-
-An optional “overwrite” flag specifies whether to overwrite a function if a
-function with the specified name already exists.
+metadata flag to set deterministic or defaultNullBehavior. An optional
+“overwrite” flag specifies whether to overwrite a function if a function
+with the specified name already exists.
 
 Use exec::registerStatefulVectorFunction to register a stateful vector
 function.