refactor: move code from types to typing_utils

in an effort to reduce number of modules

arger/main.py

@@ -6,7 +6,7 @@
 import typing as tp
 
 from .structs import Command
-from .types import F
+from .typing_utils import F
 
 CMD_TITLE = "commands"
 LEVEL = '__level__'

arger/parser/actions.py

@@ -1,8 +1,9 @@
 import argparse
 from typing import Any, Tuple, Union
 
-from ..types import UNDEFINED, VarArg, VarKw
+from ..types import VarArg, VarKw
 from ..typing_utils import (
+    UNDEFINED,
     cast,
     get_inner_args,
     get_origin,

arger/parser/classes.py

@@ -4,7 +4,7 @@
 
 from arger.parser.utils import FlagsGenerator
 
-from ..types import UNDEFINED
+from ..typing_utils import UNDEFINED
 from .actions import TypeAction
 
 

arger/parser/funcs.py

@@ -5,7 +5,8 @@
 
 from arger.parser.docstring import parse_docstring
 
-from ..types import UNDEFINED, F, T, VarArg, VarKw
+from ..types import VarArg, VarKw
+from ..typing_utils import UNDEFINED, F, T
 from .classes import Argument, Option
 from .utils import FlagsGenerator
 

arger/structs.py

@@ -4,7 +4,8 @@
 
 from .parser import parse_function
 from .parser.funcs import ParsedFunc
-from .types import F, VarArg
+from .types import VarArg
+from .typing_utils import F
 
 
 class Command:

arger/types.py

@@ -1,17 +1,4 @@
-from typing import Any, Callable, TypeVar
-
-F = TypeVar("F", bound=Callable[..., Any])  # decorator
-T = TypeVar('T')
-
-
-class _Undefined:
-    """sometimes the value could be None. we need this to distinguish such values."""
-
-    def __repr__(self):
-        return 'UNDEFINED'
-
-
-UNDEFINED = _Undefined()  # singleton
+from typing import Any
 
 
 class VarArg:

arger/typing_utils.py

@@ -2,7 +2,7 @@
 import sys
 from enum import Enum
 from inspect import isclass
-from typing import Any, FrozenSet, List, Set, Tuple
+from typing import Any, Callable, FrozenSet, List, Set, Tuple, TypeVar
 
 NEW_TYPING = sys.version_info[:3] >= (3, 7, 0)  # PEP 560
 
@@ -107,3 +107,17 @@ def cast(tp, val) -> Any:
         return origin([cast(unpack_type(tp), v) for v in val])
 
     return origin(val)
+
+
+F = TypeVar("F", bound=Callable[..., Any])  # decorator
+T = TypeVar('T')
+
+
+class _Undefined:
+    """sometimes the value could be None. we need this to distinguish such values."""
+
+    def __repr__(self):
+        return 'UNDEFINED'
+
+
+UNDEFINED = _Undefined()  # singleton

tests/test_options.py

@@ -6,7 +6,7 @@
 from arger.parser.classes import Option
 from arger.parser.funcs import Param, create_option
 from arger.parser.utils import FlagsGenerator
-from arger.types import UNDEFINED
+from arger.typing_utils import UNDEFINED
 
 
 @pytest.fixture