diff --git a/examples/health_plugin.py b/examples/health_plugin.py
deleted file mode 100644
index a795d33..0000000
--- a/examples/health_plugin.py
+++ /dev/null
@@ -1,88 +0,0 @@
-from typing import final
-
-from pydantic import Field
-
-from snakia.core.ecs import Component
-from snakia.core.ecs.system import System
-from snakia.core.engine import Engine
-from snakia.core.es import Event
-from snakia.core.loader import Meta, Plugin, PluginProcessor
-from snakia.types import Version
-
-
-class HealthComponent(Component):
-    max_value: int = Field(default=100, ge=0)
-    value: int = Field(default=100, ge=0)
-
-
-class DamageComponent(Component):
-    damage: int = Field(ge=0)
-    ticks: int = Field(default=1, ge=0)
-
-
-class HealComponent(Component):
-    heal: int = Field(ge=0)
-    ticks: int = Field(default=1, ge=0)
-
-
-class DeathEvent(Event):
-    entity: int = Field()
-
-
-class HealthProcessor(PluginProcessor):
-    def process(self, system: System) -> None:
-        for entity, (heal, health) in system.get_components(
-            HealComponent, HealthComponent
-        ):
-            health.value += heal.heal
-            heal.ticks -= 1
-            if heal.ticks <= 0:
-                system.remove_component(entity, HealComponent)
-        for entity, (damage, health) in system.get_components(
-            DamageComponent, HealthComponent
-        ):
-            health.value -= damage.damage
-            damage.ticks -= 1
-            if damage.ticks <= 0:
-                system.remove_component(entity, DamageComponent)
-            if health.value <= 0:
-                system.remove_component(entity, HealthComponent)
-                self.plugin.dispatcher.publish(DeathEvent(entity=entity))
-
-
-@final
-class HealthPlugin(
-    Plugin,
-    meta=Meta(
-        name="health",
-        author="snakia",
-        version=Version.from_args(1, 0, 0),
-        subscribers=(),
-        processors=(HealthProcessor,),
-    ),
-):
-    def on_load(self) -> None:
-        pass
-
-    def on_unload(self) -> None:
-        pass
-
-
-def main() -> None:
-    engine = Engine()
-    engine.loader.register(HealthPlugin)
-    engine.loader.load_all()
-
-    @engine.dispatcher.on(DeathEvent)
-    def on_death(event: DeathEvent) -> None:
-        print(f"Entity: {event.entity} is death!")
-
-    player = engine.system.create_entity()
-    engine.system.add_component(player, HealthComponent())
-    engine.system.add_component(player, DamageComponent(damage=10, ticks=10))
-
-    engine.start()
-
-
-if __name__ == "__main__":
-    main()
diff --git a/py.typed b/py.typed
new file mode 100644
index 0000000..e69de29
diff --git a/pyproject.toml b/pyproject.toml
index d9fa955..9d48e55 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -26,7 +26,7 @@ dependencies = [
     "types-networkx>=3.5.0.20251106",
     "typing-extensions>=4.15.0",
 ]
-license = "CC0-1.0"
+license = "Unlicense"
 license-files = ["LICENSE"]
 
 [project.urls]
diff --git a/src/snakia/core/engine.py b/src/snakia/core/engine.py
index 047c26e..a4f47b2 100644
--- a/src/snakia/core/engine.py
+++ b/src/snakia/core/engine.py
@@ -3,14 +3,12 @@ from typing import Final
 
 from .ecs import System
 from .es import Dispatcher
-from .loader.loader import Loader
 
 
 class Engine:
     __slots__ = (
         "system",
         "dispatcher",
-        "loader",
         "__system_thread",
         "__dispatcher_thread",
     )
@@ -18,12 +16,13 @@ class Engine:
     def __init__(self) -> None:
         self.system: Final = System()
         self.dispatcher: Final = Dispatcher()
-        self.loader: Final = Loader(self)
         self.__system_thread: threading.Thread | None = None
         self.__dispatcher_thread: threading.Thread | None = None
 
     def start(self) -> None:
-        self.__system_thread = threading.Thread(target=self.system.start, daemon=False)
+        self.__system_thread = threading.Thread(
+            target=self.system.start, daemon=False
+        )
         self.__dispatcher_thread = threading.Thread(
             target=self.dispatcher.start, daemon=False
         )
diff --git a/src/snakia/core/loader/__init__.py b/src/snakia/core/loader/__init__.py
deleted file mode 100644
index 9e099c5..0000000
--- a/src/snakia/core/loader/__init__.py
+++ /dev/null
@@ -1,6 +0,0 @@
-from .loadable import Loadable
-from .meta import Meta
-from .plugin import Plugin
-from .plugin_processor import PluginProcessor
-
-__all__ = ["Loadable", "Meta", "Plugin", "PluginProcessor"]
diff --git a/src/snakia/core/loader/loadable.py b/src/snakia/core/loader/loadable.py
deleted file mode 100644
index 51e75d0..0000000
--- a/src/snakia/core/loader/loadable.py
+++ /dev/null
@@ -1,18 +0,0 @@
-from __future__ import annotations
-
-from abc import ABC, abstractmethod
-from typing import TYPE_CHECKING
-
-if TYPE_CHECKING:
-    from snakia.core.engine import Engine
-
-
-class Loadable(ABC):
-    @abstractmethod
-    def __init__(self, engine: Engine) -> None: ...
-
-    @abstractmethod
-    def load(self) -> None: ...
-
-    @abstractmethod
-    def unload(self) -> None: ...
diff --git a/src/snakia/core/loader/loader.py b/src/snakia/core/loader/loader.py
deleted file mode 100644
index 0dcf807..0000000
--- a/src/snakia/core/loader/loader.py
+++ /dev/null
@@ -1,26 +0,0 @@
-from __future__ import annotations
-
-from typing import TYPE_CHECKING, Callable, Final
-
-if TYPE_CHECKING:
-    from snakia.core.engine import Engine
-    from snakia.core.loader import Loadable
-
-
-class Loader:
-    __slots__ = ("__engine", "__loadables")
-
-    def __init__(self, engine: Engine) -> None:
-        self.__engine: Final = engine
-        self.__loadables: Final[list[Loadable]] = []
-
-    def register(self, loadable: Callable[[Engine], Loadable]) -> None:
-        self.__loadables.append(loadable(self.__engine))
-
-    def load_all(self) -> None:
-        for loadable in self.__loadables:
-            loadable.load()
-
-    def unload_all(self) -> None:
-        for loadable in reversed(self.__loadables):
-            loadable.unload()
diff --git a/src/snakia/core/loader/meta.py b/src/snakia/core/loader/meta.py
deleted file mode 100644
index 429d4b4..0000000
--- a/src/snakia/core/loader/meta.py
+++ /dev/null
@@ -1,35 +0,0 @@
-from __future__ import annotations
-
-from pydantic import BaseModel, ConfigDict, Field
-
-from snakia.core.es import Event, Subscriber
-from snakia.types import Version
-
-from .plugin_processor import PluginProcessor
-
-
-class Meta(BaseModel):
-    model_config = ConfigDict(frozen=True, arbitrary_types_allowed=True)
-
-    name: str = Field(
-        default="unknown",
-        min_length=4,
-        max_length=32,
-        pattern="^[a-z0-9_]{4,32}$",
-    )
-    author: str = Field(
-        default="unknown",
-        min_length=4,
-        max_length=32,
-        pattern="^[a-z0-9_]{4,32}$",
-    )
-    version: Version = Field(default_factory=lambda: Version(major=1, minor=0, patch=0))
-
-    subscribers: tuple[tuple[type[Event], Subscriber[Event]], ...] = Field(
-        default_factory=tuple
-    )
-    processors: tuple[type[PluginProcessor], ...] = Field(default_factory=tuple)
-
-    @property
-    def id(self) -> str:
-        return f"{self.author}.{self.name}"
diff --git a/src/snakia/core/loader/plugin.py b/src/snakia/core/loader/plugin.py
deleted file mode 100644
index f8abfa5..0000000
--- a/src/snakia/core/loader/plugin.py
+++ /dev/null
@@ -1,72 +0,0 @@
-from __future__ import annotations
-
-from abc import abstractmethod
-from typing import TYPE_CHECKING, ClassVar, Final, final
-
-from snakia.core.ecs import System
-from snakia.core.es import Dispatcher
-
-from .loadable import Loadable
-from .meta import Meta
-
-if TYPE_CHECKING:
-    from snakia.core.engine import Engine
-
-
-class Plugin(Loadable):
-    __meta: ClassVar[Meta]
-
-    @final
-    def __init__(self, engine: Engine) -> None:
-        self.__engine: Final = engine
-
-    @final
-    @property
-    def meta(self) -> Meta:
-        """The plugin's metadata."""
-        return self.__meta
-
-    @final
-    @property
-    def dispatcher(self) -> Dispatcher:
-        return self.__engine.dispatcher
-
-    @final
-    @property
-    def system(self) -> System:
-        return self.__engine.system
-
-    @final
-    def load(self) -> None:
-        for processor in self.meta.processors:
-            self.__engine.system.add_processor(processor(self))
-        for event_type, subscriber in self.meta.subscribers:
-            self.__engine.dispatcher.subscribe(event_type, subscriber)
-        self.on_load()
-
-    @final
-    def unload(self) -> None:
-        for processor in self.meta.processors:
-            self.__engine.system.remove_processor(processor)
-        for event_type, subscriber in self.meta.subscribers:
-            self.__engine.dispatcher.unsubscribe(event_type, subscriber)
-        self.on_unload()
-
-    @abstractmethod
-    def on_load(self) -> None:
-        pass
-
-    @abstractmethod
-    def on_unload(self) -> None:
-        pass
-
-    if TYPE_CHECKING:
-
-        @final
-        def __init_subclass__(cls, meta: Meta) -> None:
-            pass
-
-    else:
-
-        def __init_subclass__(cls, meta: Meta) -> None:
-            cls.meta = meta
diff --git a/src/snakia/core/loader/plugin_processor.py b/src/snakia/core/loader/plugin_processor.py
deleted file mode 100644
index f959327..0000000
--- a/src/snakia/core/loader/plugin_processor.py
+++ /dev/null
@@ -1,14 +0,0 @@
-from __future__ import annotations
-
-from typing import TYPE_CHECKING, Final, final
-
-from snakia.core.ecs import Processor
-
-if TYPE_CHECKING:
-    from .plugin import Plugin
-
-
-class PluginProcessor(Processor):
-    @final
-    def __init__(self, plugin: Plugin) -> None:
-        self.plugin: Final = plugin
diff --git a/src/snakia/core/rx/base_bindable.py b/src/snakia/core/rx/base_bindable.py
index b229821..bd8c73b 100644
--- a/src/snakia/core/rx/base_bindable.py
+++ b/src/snakia/core/rx/base_bindable.py
@@ -29,8 +29,7 @@ class BaseBindable(Generic[T]):
     def value(self) -> T:
         if self.has_value:
             return self.__value
-        else:
-            return self.default_value
+        return self.default_value
 
     @property
     def has_value(self) -> bool:
diff --git a/src/snakia/core/rx/combines.py b/src/snakia/core/rx/combines.py
index 345d0a7..23c6675 100644
--- a/src/snakia/core/rx/combines.py
+++ b/src/snakia/core/rx/combines.py
@@ -95,7 +95,7 @@ def combine(
     )
 
     def subscriber(_: ValueChanged[Any]) -> None:
-        combined.set(combiner(*[*map(lambda s: s.value, sources)]))
+        combined.set(combiner(*map(lambda s: s.value, sources)))
 
     for source in sources:
         if isinstance(source, Bindable):
@@ -185,7 +185,7 @@ def async_combine(
     )
 
     async def subscriber(_: ValueChanged[Any]) -> None:
-        result = await combiner(*[*map(lambda s: s.value, sources)])
+        result = await combiner(*map(lambda s: s.value, sources))
         await combined.set(result)
 
     for source in sources:
diff --git a/src/snakia/field/__init__.py b/src/snakia/field/__init__.py
index 654fdd9..e95ce46 100644
--- a/src/snakia/field/__init__.py
+++ b/src/snakia/field/__init__.py
@@ -3,6 +3,8 @@ from .bool import BoolField
 from .field import Field
 from .float import FloatField
 from .int import IntField
+from .list import ListField
+from .optional import OptionalField
 from .str import StrField
 
 __all__ = [
@@ -11,5 +13,7 @@ __all__ = [
     "BoolField",
     "FloatField",
     "IntField",
+    "ListField",
+    "OptionalField",
     "StrField",
 ]
diff --git a/src/snakia/field/auto.py b/src/snakia/field/auto.py
index 1216a30..f456a1d 100644
--- a/src/snakia/field/auto.py
+++ b/src/snakia/field/auto.py
@@ -1,5 +1,9 @@
 import pickle
-from typing import Final, Generic, TypeVar
+from typing import Callable, Final, Generic, TypeVar, overload
+
+from typing_extensions import Self
+
+from snakia.types import Unset
 
 from .field import Field
 
@@ -9,15 +13,40 @@ T = TypeVar("T")
 class AutoField(Field[T], Generic[T]):
     __slots__ = ("__target_type",)
 
-    def __init__(self, default_value: T, *, target_type: type[T] | None = None) -> None:
-        super().__init__(default_value)
-        self.__target_type: Final = target_type
+    @overload
+    def __init__(
+        self, default_value: T, *, target_type: type[T] | Unset = Unset()
+    ) -> None: ...
+
+    @overload
+    def __init__(
+        self,
+        *,
+        default_factory: Callable[[Self], T],
+        target_type: type[T] | Unset = Unset(),
+    ) -> None: ...
+
+    def __init__(
+        self,
+        default_value: T | Unset = Unset(),
+        *,
+        default_factory: Callable[[Self], T] | Unset = Unset(),
+        target_type: type[T] | Unset = Unset(),
+    ) -> None:
+        if not Unset.itis(default_factory):
+            super().__init__(default_factory=Unset.unwrap(default_factory))
+        elif not Unset.itis(default_value):
+            super().__init__(Unset.unwrap(default_value))
+        else:
+            super().__init__()
+        self.__target_type: Final[type] = Unset.unwrap_or(target_type, object)
 
     def serialize(self, value: T, /) -> bytes:
         return pickle.dumps(value)
 
     def deserialize(self, serialized: bytes, /) -> T:
         value = pickle.loads(serialized)
-        if not isinstance(value, self.__target_type or object):
-            return self.default_value
+        
+        if not isinstance(value, self.__target_type):
+            return self._get_default()
         return value  # type: ignore
diff --git a/src/snakia/field/field.py b/src/snakia/field/field.py
index 628b7c7..57e9de6 100644
--- a/src/snakia/field/field.py
+++ b/src/snakia/field/field.py
@@ -1,7 +1,14 @@
 from __future__ import annotations
 
 from abc import ABC, abstractmethod
-from typing import TYPE_CHECKING, Any, Callable, Final, Generic, TypeVar, final
+from typing import (
+    TYPE_CHECKING,
+    Any,
+    Callable,
+    Generic,
+    TypeVar,
+    final,
+)
 
 from snakia.property.priv_property import PrivProperty
 from snakia.utils import inherit
@@ -11,10 +18,6 @@ R = TypeVar("R")
 
 
 class Field(ABC, PrivProperty[T], Generic[T]):
-    def __init__(self, default_value: T) -> None:
-        self.default_value: Final[T] = default_value
-        super().__init__(default_value)
-
     @abstractmethod
     def serialize(self, value: T, /) -> bytes:
         """Serialize a value
@@ -42,14 +45,18 @@ class Field(ABC, PrivProperty[T], Generic[T]):
         serialize: Callable[[Field[R], R], bytes],
         deserialize: Callable[[Field[R], bytes], R],
     ) -> type[Field[R]]:
-        return inherit(cls, {"serialize": serialize, "deserialize": deserialize})
+        return inherit(
+            cls, {"serialize": serialize, "deserialize": deserialize}
+        )
 
     @final
     @staticmethod
     def get_fields(class_: type[Any] | Any, /) -> dict[str, Field[Any]]:
         if not isinstance(class_, type):
             class_ = class_.__class__
-        return {k: v for k, v in class_.__dict__.items() if isinstance(v, Field)}
+        return {
+            k: v for k, v in class_.__dict__.items() if isinstance(v, Field)
+        }
 
     if TYPE_CHECKING:
 
diff --git a/src/snakia/field/list.py b/src/snakia/field/list.py
new file mode 100644
index 0000000..f2671da
--- /dev/null
+++ b/src/snakia/field/list.py
@@ -0,0 +1,38 @@
+from typing import Callable, Final, Iterable, TypeVar
+
+from typing_extensions import Self
+
+from .field import Field
+
+T = TypeVar("T")
+
+
+class ListField(Field[list[T]]):
+    def __init__(
+        self,
+        field: Field[T],
+        *,
+        length_size: int = 1,
+        default_factory: Callable[[Self], Iterable[T]] = lambda _: (),
+    ) -> None:
+        self.length_size: Final[int] = length_size
+        self.field: Final = field
+        super().__init__(default_factory=lambda s: [*default_factory(s)])
+
+    def serialize(self, items: list[T], /) -> bytes:
+        result = b""
+        for item in items:
+            value = self.field.serialize(item)
+            length_prefix = len(value).to_bytes(self.length_size, "big")
+            result += length_prefix + value
+        return result
+
+    def deserialize(self, serialized: bytes, /) -> list[T]:
+        result = []
+        while serialized:
+            length = int.from_bytes(serialized[: self.length_size], "big")
+            serialized = serialized[self.length_size :]
+            item = self.field.deserialize(serialized[:length])
+            serialized = serialized[length:]
+            result.append(item)
+        return result
diff --git a/src/snakia/field/optional.py b/src/snakia/field/optional.py
new file mode 100644
index 0000000..eb437c0
--- /dev/null
+++ b/src/snakia/field/optional.py
@@ -0,0 +1,28 @@
+from typing import Final, TypeVar
+
+from .field import Field
+
+T = TypeVar("T")
+
+
+class OptionalField(Field[T | None]):
+
+    def __init__(
+        self,
+        field: Field[T],
+        *,
+        none_value: bytes = b"",
+    ) -> None:
+        super().__init__(None)
+        self.none_value: Final = none_value
+        self.field: Final = field
+
+    def serialize(self, value: T | None, /) -> bytes:
+        if value is None:
+            return self.none_value
+        return self.field.serialize(value)
+
+    def deserialize(self, serialized: bytes, /) -> T | None:
+        if serialized == self.none_value:
+            return None
+        return self.field.deserialize(serialized)
diff --git a/src/snakia/field/t.py b/src/snakia/field/t.py
index f535738..abb404b 100644
--- a/src/snakia/field/t.py
+++ b/src/snakia/field/t.py
@@ -4,6 +4,8 @@ from .bool import BoolField as bool
 from .field import Field as field
 from .float import FloatField as float
 from .int import IntField as int
+from .list import ListField as list
+from .optional import OptionalField as optional
 from .str import StrField as str
 
 __all__ = [
@@ -12,5 +14,7 @@ __all__ = [
     "field",
     "float",
     "int",
+    "list",
+    "optional",
     "str",
 ]
diff --git a/src/snakia/property/priv_property.py b/src/snakia/property/priv_property.py
index 1a85e09..fba63da 100644
--- a/src/snakia/property/priv_property.py
+++ b/src/snakia/property/priv_property.py
@@ -1,22 +1,44 @@
-from typing import Any, Generic, TypeVar
+from typing import Any, Callable, Final, Generic, TypeVar, overload
+
+from typing_extensions import Self
+
+from snakia.types import Unset
 
 T = TypeVar("T")
 
 
 class PrivProperty(Generic[T]):
-    __slots__ = "__name", "__default_value"
+    __slots__ = "__name", "__default_value", "__default_factory"
 
     __name: str
 
-    def __init__(self, default_value: T | None = None) -> None:
-        self.__default_value: T | None = default_value
+    @overload
+    def __init__(self) -> None: ...
+    @overload
+    def __init__(self, default_value: T) -> None: ...
+    @overload
+    def __init__(self, *, default_factory: Callable[[Self], T]) -> None: ...
+    def __init__(
+        self,
+        default_value: T | Unset = Unset(),
+        default_factory: Callable[[Self], T] | Unset = Unset(),
+    ) -> None:
+        self.__default_value: Final[T | Unset] = default_value
+        self.__default_factory: Final[Callable[[Self], T] | Unset] = default_factory
+
+    def _get_default(self: Self) -> T:
+        return Unset.map(
+            self.__default_factory,
+            lambda f: f(self),
+            lambda _: Unset.unwrap(self.__default_value),
+        )
 
     def __set_name__(self, owner: type, name: str) -> None:
         self.__name = f"_{owner.__name__}__{name}"
 
     def __get__(self, instance: Any, owner: type | None = None, /) -> T:
-        if self.__default_value:
-            return getattr(instance, self.__name, self.__default_value)
+        if not hasattr(instance, self.__name):
+            setattr(instance, self.__name, self._get_default())
         return getattr(instance, self.__name)  # type: ignore
 
     def __set__(self, instance: Any, value: T, /) -> None:
diff --git a/src/snakia/types/marker.py b/src/snakia/types/marker.py
index 002e2ec..3024fb9 100644
--- a/src/snakia/types/marker.py
+++ b/src/snakia/types/marker.py
@@ -12,7 +12,7 @@ MARKERS_ATTR = "__snakia_markers__"
 
 
 def _get_all_markers(obj: Any) -> dict[type["Marker"], "Marker"]:
-    return get_or_set_attr(obj, MARKERS_ATTR, dict[type[Marker], Marker]())
+    return get_or_set_attr(obj, MARKERS_ATTR, dict())
 
 
 class Marker:
diff --git a/src/snakia/types/unique.py b/src/snakia/types/unique.py
index 3c149fd..2f66e0f 100644
--- a/src/snakia/types/unique.py
+++ b/src/snakia/types/unique.py
@@ -49,24 +49,29 @@ class UniqueType(type):
             raise TypeError(f"{cls} not unwrapped")
         return value  # type: ignore
 
+    def unwrap_or(cls: type[T], value: V | type[T] | T, default: R, /) -> V | R:
+        if value is cls or isinstance(value, cls):
+            return default
+        return value  # type: ignore
+
     def map(
         cls: type[T],
         value: V | type[T] | T,
-        and_then: Callable[[V], R],
-        or_else: Callable[[type[T]], R],
+        or_else: Callable[[V], R],
+        and_then: Callable[[type[T]], R],
     ) -> R:
         if value is cls or isinstance(value, cls):
-            return or_else(cls)
-        return and_then(value)  # type: ignore
+            return and_then(cls)
+        return or_else(value)  # type: ignore
 
-    def and_then(
+    def or_else(
         cls: type[T], value: V | type[T] | T, func: Callable[[V], R]
     ) -> type[T] | R:
         if value is cls or isinstance(value, cls):
             return cls
         return func(value)  # type: ignore
 
-    def or_else(
+    def and_then(
         cls: type[T], value: V | type[T] | T, func: Callable[[type[T]], R]
     ) -> R | V:
         if value is cls or isinstance(value, cls):
diff --git a/src/snakia/utils/__init__.py b/src/snakia/utils/__init__.py
index 353803d..ad6100d 100644
--- a/src/snakia/utils/__init__.py
+++ b/src/snakia/utils/__init__.py
@@ -1,10 +1,9 @@
 from .attrs import get_attrs, get_or_set_attr
-from .calls import call, caller
 from .exceptions import catch, throw
 from .frames import frame
+from .funcs import call, caller, ret, side, side_func
 from .gil import GIL_ENABLED, nolock
 from .inherit import inherit
-from .side import side, side_func
 from .this import this
 from .to_async import to_async
 
@@ -17,6 +16,7 @@ __all__ = [
     "frame",
     "inherit",
     "nolock",
+    "ret",
     "side",
     "side_func",
     "this",
diff --git a/src/snakia/utils/calls.py b/src/snakia/utils/calls.py
deleted file mode 100644
index eeabd5f..0000000
--- a/src/snakia/utils/calls.py
+++ /dev/null
@@ -1,12 +0,0 @@
-from typing import Callable, ParamSpec, TypeVar
-
-P = ParamSpec("P")
-T = TypeVar("T")
-
-
-def call(f: Callable[P, T], *args: P.args, **kwargs: P.kwargs) -> T:
-    return f(*args, **kwargs)
-
-
-def caller(f: Callable[P, T], *args: P.args, **kwargs: P.kwargs) -> Callable[..., T]:
-    return lambda *_, **__: f(*args, **kwargs)
diff --git a/src/snakia/utils/funcs.py b/src/snakia/utils/funcs.py
new file mode 100644
index 0000000..94cdad4
--- /dev/null
+++ b/src/snakia/utils/funcs.py
@@ -0,0 +1,24 @@
+from typing import Any, Callable, ParamSpec, TypeVar
+
+P = ParamSpec("P")
+T = TypeVar("T")
+
+
+def call(f: Callable[P, T], *args: P.args, **kwargs: P.kwargs) -> T:
+    return f(*args, **kwargs)
+
+
+def caller(f: Callable[P, T], *args: P.args, **kwargs: P.kwargs) -> Callable[..., T]:
+    return lambda *_, **__: f(*args, **kwargs)
+
+
+def side(value: T, *_: Any, **__: Any) -> T:
+    return value
+
+
+def side_func(value: T, *_: Any, **__: Any) -> Callable[..., T]:
+    return lambda *_, **__: value
+
+
+def ret() -> Callable[[T], T]:
+    return lambda x: x
diff --git a/src/snakia/utils/side.py b/src/snakia/utils/side.py
deleted file mode 100644
index 985e919..0000000
--- a/src/snakia/utils/side.py
+++ /dev/null
@@ -1,11 +0,0 @@
-from typing import Any, Callable, TypeVar
-
-T = TypeVar("T")
-
-
-def side(value: T, *_: Any, **__: Any) -> T:
-    return value
-
-
-def side_func(value: T, *_: Any, **__: Any) -> Callable[..., T]:
-    return lambda *_, **__: value