1 files changed, 25 insertions, 45 deletions

diff --git a/lib/sqlalchemy/sql/functions.py b/lib/sqlalchemy/sql/functions.py
index cbc8e539f..96e64dc28 100644
--- a/lib/sqlalchemy/sql/functions.py
+++ b/lib/sqlalchemy/sql/functions.py
@@ -17,7 +17,6 @@ from . import sqltypes
 from . import util as sqlutil
 from .base import ColumnCollection
 from .base import Executable
-from .elements import _clone
 from .elements import _type_from_args
 from .elements import BinaryExpression
 from .elements import BindParameter
@@ -33,7 +32,8 @@ from .elements import WithinGroup
 from .selectable import Alias
 from .selectable import FromClause
 from .selectable import Select
-from .visitors import VisitableType
+from .visitors import InternalTraversal
+from .visitors import TraversibleType
 from .. import util
 
 
@@ -78,10 +78,14 @@ class FunctionElement(Executable, ColumnElement, FromClause):
 
     """
 
+    _traverse_internals = [("clause_expr", InternalTraversal.dp_clauseelement)]
+
     packagenames = ()
 
     _has_args = False
 
+    _memoized_property = FromClause._memoized_property
+
     def __init__(self, *clauses, **kwargs):
         r"""Construct a :class:`.FunctionElement`.
 
@@ -136,7 +140,7 @@ class FunctionElement(Executable, ColumnElement, FromClause):
         col = self.label(None)
         return ColumnCollection(columns=[(col.key, col)])
 
-    @util.memoized_property
+    @_memoized_property
     def clauses(self):
         """Return the underlying :class:`.ClauseList` which contains
         the arguments for this :class:`.FunctionElement`.
@@ -283,17 +287,6 @@ class FunctionElement(Executable, ColumnElement, FromClause):
     def _from_objects(self):
         return self.clauses._from_objects
 
-    def get_children(self, **kwargs):
-        return (self.clause_expr,)
-
-    def _cache_key(self, **kw):
-        return (FunctionElement, self.clause_expr._cache_key(**kw))
-
-    def _copy_internals(self, clone=_clone, **kw):
-        self.clause_expr = clone(self.clause_expr, **kw)
-        self._reset_exported()
-        FunctionElement.clauses._reset(self)
-
     def within_group_type(self, within_group):
         """For types that define their return type as based on the criteria
         within a WITHIN GROUP (ORDER BY) expression, called by the
@@ -404,6 +397,13 @@ class FunctionElement(Executable, ColumnElement, FromClause):
 
 
 class FunctionAsBinary(BinaryExpression):
+    _traverse_internals = [
+        ("sql_function", InternalTraversal.dp_clauseelement),
+        ("left_index", InternalTraversal.dp_plain_obj),
+        ("right_index", InternalTraversal.dp_plain_obj),
+        ("modifiers", InternalTraversal.dp_plain_dict),
+    ]
+
     def __init__(self, fn, left_index, right_index):
         self.sql_function = fn
         self.left_index = left_index
@@ -431,20 +431,6 @@ class FunctionAsBinary(BinaryExpression):
     def right(self, value):
         self.sql_function.clauses.clauses[self.right_index - 1] = value
 
-    def _copy_internals(self, clone=_clone, **kw):
-        self.sql_function = clone(self.sql_function, **kw)
-
-    def get_children(self, **kw):
-        yield self.sql_function
-
-    def _cache_key(self, **kw):
-        return (
-            FunctionAsBinary,
-            self.sql_function._cache_key(**kw),
-            self.left_index,
-            self.right_index,
-        )
-
 
 class _FunctionGenerator(object):
     """Generate SQL function expressions.
@@ -606,6 +592,12 @@ class Function(FunctionElement):
 
     __visit_name__ = "function"
 
+    _traverse_internals = FunctionElement._traverse_internals + [
+        ("packagenames", InternalTraversal.dp_plain_obj),
+        ("name", InternalTraversal.dp_string),
+        ("type", InternalTraversal.dp_type),
+    ]
+
     def __init__(self, name, *clauses, **kw):
         """Construct a :class:`.Function`.
 
@@ -630,15 +622,8 @@ class Function(FunctionElement):
             unique=True,
         )
 
-    def _cache_key(self, **kw):
-        return (
-            (Function,) + tuple(self.packagenames)
-            if self.packagenames
-            else () + (self.name, self.clause_expr._cache_key(**kw))
-        )
-
 
-class _GenericMeta(VisitableType):
+class _GenericMeta(TraversibleType):
     def __init__(cls, clsname, bases, clsdict):
         if annotation.Annotated not in cls.__mro__:
             cls.name = name = clsdict.get("name", clsname)
@@ -764,6 +749,10 @@ class next_value(GenericFunction):
     type = sqltypes.Integer()
     name = "next_value"
 
+    _traverse_internals = [
+        ("sequence", InternalTraversal.dp_named_ddl_element)
+    ]
+
     def __init__(self, seq, **kw):
         assert isinstance(
             seq, schema.Sequence
@@ -771,21 +760,12 @@ class next_value(GenericFunction):
         self._bind = kw.get("bind", None)
         self.sequence = seq
 
-    def _cache_key(self, **kw):
-        return (next_value, self.sequence.name)
-
     def compare(self, other, **kw):
         return (
             isinstance(other, next_value)
             and self.sequence.name == other.sequence.name
         )
 
-    def get_children(self, **kwargs):
-        return []
-
-    def _copy_internals(self, **kw):
-        pass
-
     @property
     def _from_objects(self):
         return []