move a bunch of imports into TYPE_CHECKING blocks

These are only used for type checking, so don't bother importing them at
runtime.

Generally add future annotations at the same time, to make sure that
existing uses of these imports don't need to be quoted.

3 files changed, 11 insertions, 7 deletions

diff --git a/mesonbuild/interpreterbase/decorators.py b/mesonbuild/interpreterbase/decorators.py
index 672ef5b9f..e678fd97f 100644
--- a/mesonbuild/interpreterbase/decorators.py
+++ b/mesonbuild/interpreterbase/decorators.py
@@ -11,12 +11,11 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+from __future__ import annotations
 
 from .. import mesonlib, mlog
-from .baseobjects import TV_func, TYPE_var, TYPE_kwargs
 from .disabler import Disabler
 from .exceptions import InterpreterException, InvalidArguments
-from .operator import MesonOperator
 from ._unholder import _unholder
 
 from dataclasses import dataclass
@@ -30,8 +29,9 @@ if T.TYPE_CHECKING:
     from typing_extensions import Protocol
 
     from .. import mparser
-    from .baseobjects import InterpreterObject
+    from .baseobjects import InterpreterObject, TV_func, TYPE_var, TYPE_kwargs
     from .interpreterbase import SubProject
+    from .operator import MesonOperator
 
     _TV_IntegerObject = T.TypeVar('_TV_IntegerObject', bound=InterpreterObject, contravariant=True)
     _TV_ARG1 = T.TypeVar('_TV_ARG1', bound=TYPE_var, contravariant=True)
diff --git a/mesonbuild/interpreterbase/disabler.py b/mesonbuild/interpreterbase/disabler.py
index 63b914e59..182bb625c 100644
--- a/mesonbuild/interpreterbase/disabler.py
+++ b/mesonbuild/interpreterbase/disabler.py
@@ -11,10 +11,15 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+from __future__ import annotations
 
-from .baseobjects import MesonInterpreterObject, TYPE_var, TYPE_kwargs
 import typing as T
 
+from .baseobjects import MesonInterpreterObject
+
+if T.TYPE_CHECKING:
+    from .baseobjects import TYPE_var, TYPE_kwargs
+
 class Disabler(MesonInterpreterObject):
     def method_call(self, method_name: str, args: T.List[TYPE_var], kwargs: TYPE_kwargs) -> TYPE_var:
         if method_name == 'found':
diff --git a/mesonbuild/interpreterbase/interpreterbase.py b/mesonbuild/interpreterbase/interpreterbase.py
index 28211b051..85aabd163 100644
--- a/mesonbuild/interpreterbase/interpreterbase.py
+++ b/mesonbuild/interpreterbase/interpreterbase.py
@@ -14,6 +14,7 @@
 
 # This class contains the basic functionality needed to run any interpreter
 # or an interpreter-based tool.
+from __future__ import annotations
 
 from .. import mparser, mesonlib
 from .. import environment
@@ -26,10 +27,7 @@ from .baseobjects import (
     ObjectHolder,
     IterableObject,
 
-    SubProject,
-
     TYPE_var,
-    TYPE_kwargs,
 
     HoldableTypes,
 )
@@ -54,6 +52,7 @@ import typing as T
 import textwrap
 
 if T.TYPE_CHECKING:
+    from .baseobjects import SubProject, TYPE_kwargs
     from ..interpreter import Interpreter
 
 HolderMapType = T.Dict[