Propose Result as immediate replacement for ResultProxy

As progress is made on the _future.Result, including breaking
it out such that DBAPI behaviors are local to specific
implementations, it becomes apparent that the Result object
is a functional superset of ResultProxy and that basic
operations like fetchone(), fetchall(), and fetchmany()
behave pretty much exactly the same way on the new object.
Reorganize things so that ResultProxy is now referred to
as LegacyCursorResult, which subclasses CursorResult
that represents the DBAPI-cursor version of Result,
making use of a multiple inheritance pattern so that
the functionality of Result is also available in non-DBAPI
contexts, as will be necessary for some ORM
patterns.

Additionally propose the composition system for Result
that will form the basis for ORM-alternative result
systems such as horizontal sharding and dogpile cache.
As ORM results will soon be coming directly from
instances of Result, these extensions will instead
build their own ResultFetchStrategies that perform
the special steps to create composed or cached
result sets.

Also considering at the moment not emitting deprecation
warnings for fetchXYZ() methods; the immediate issue
is Keystone tests are calling upon it, but as the
implementations here are proving to be not in any
kind of conflict with how Result works, there's
not too much issue leaving them around and deprecating
at some later point.

References: #5087
References: #4395
Fixes: #4959
Change-Id: I8091919d45421e3f53029b8660427f844fee0228

1 files changed, 12 insertions, 20 deletions

diff --git a/lib/sqlalchemy/engine/__init__.py b/lib/sqlalchemy/engine/__init__.py
index db5f9dee7..8419cf920 100644
--- a/lib/sqlalchemy/engine/__init__.py
+++ b/lib/sqlalchemy/engine/__init__.py
@@ -25,6 +25,13 @@ from .base import Transaction  # noqa
 from .base import TwoPhaseTransaction  # noqa
 from .create import create_engine
 from .create import engine_from_config
+from .cursor import BaseCursorResult  # noqa
+from .cursor import BufferedColumnResultProxy  # noqa
+from .cursor import BufferedColumnRow  # noqa
+from .cursor import BufferedRowResultProxy  # noqa
+from .cursor import CursorResult  # noqa
+from .cursor import FullyBufferedResultProxy  # noqa
+from .cursor import LegacyCursorResult  # noqa
 from .interfaces import Compiled  # noqa
 from .interfaces import Connectable  # noqa
 from .interfaces import CreateEnginePlugin  # noqa
@@ -33,29 +40,14 @@ from .interfaces import ExceptionContext  # noqa
 from .interfaces import ExecutionContext  # noqa
 from .interfaces import TypeCompiler  # noqa
 from .mock import create_mock_engine
-from .result import BaseResult  # noqa
-from .result import BaseRow  # noqa
-from .result import BufferedColumnResultProxy  # noqa
-from .result import BufferedColumnRow  # noqa
-from .result import BufferedRowResultProxy  # noqa
-from .result import FullyBufferedResultProxy  # noqa
-from .result import LegacyRow  # noqa
+from .result import Result  # noqa
 from .result import result_tuple  # noqa
-from .result import ResultProxy  # noqa
-from .result import Row  # noqa
-from .result import RowMapping  # noqa
+from .row import BaseRow  # noqa
+from .row import LegacyRow  # noqa
+from .row import Row  # noqa
+from .row import RowMapping  # noqa
 from .util import connection_memoize  # noqa
 from ..sql import ddl  # noqa
 
 
 __all__ = ("create_engine", "engine_from_config", "create_mock_engine")
-
-
-def __go(lcls):
-    from .. import future
-    from . import result
-
-    result._future_Result = future.Result
-
-
-__go(locals())