1 files changed, 92 insertions, 0 deletions
diff --git a/tools/cru-py/cru/_meta.py b/tools/cru-py/cru/_meta.py
new file mode 100644
index 0000000..86763cf
--- /dev/null
+++ b/tools/cru-py/cru/_meta.py
@@ -0,0 +1,92 @@
+from collections.abc import Callable
+from typing import Concatenate, Generic, ParamSpec, TypeVar
+
+_P = ParamSpec("_P")
+_T = TypeVar("_T")
+_O = TypeVar("_O")
+_R = TypeVar("_R")
+
+
+class CruDecorator:
+
+    class ImplementedBy(Generic[_O, _P, _R]):
+        # TODO: Continue here tomorrow!
+        def __init__(
+            self, impl: Callable[Concatenate[_O, _P], _R], pass_self: bool
+        ) -> None:
+            self.impl = impl
+            self.pass_self = pass_self
+
+        def __call__(
+            self, _origin: Callable[[_T], None]
+        ) -> Callable[Concatenate[_T, _P], _R]:
+            def real_impl(_self: _T, *args: _P.args, **kwargs: _P.kwargs) -> _R:
+                if self.pass_self:
+                    return self.impl(_self, *args, **kwargs)
+                else:
+                    return self.impl(*args, **kwargs)
+
+            return real_impl
+
+    @staticmethod
+    def convert_result(
+        converter: Callable[[_T], _O]
+    ) -> Callable[[Callable[_P, _T]], Callable[_P, _O]]:
+        def dec(original: Callable[_P, _T]) -> Callable[_P, _O]:
+            def wrapped(*args: _P.args, **kwargs: _P.kwargs) -> _O:
+                return converter(original(*args, **kwargs))
+
+            return wrapped
+
+        return dec
+
+    @staticmethod
+    def create_implement_by(converter: Callable[[_T], _O]) -> Callable[
+        [Callable[Concatenate[_O, _P], _R]],
+        Callable[
+            [Callable[[_T], None]],
+            Callable[Concatenate[_T, _P], _R],
+        ],
+    ]:
+        def implement_by(
+            m: Callable[Concatenate[_O, _P], _R],
+        ) -> Callable[
+            [Callable[[_T], None]],
+            Callable[Concatenate[_T, _P], _R],
+        ]:
+            def implementation(_self: _T, *args: _P.args, **kwargs: _P.kwargs) -> _R:
+                return m(converter(_self), *args, **kwargs)
+
+            def decorator(_: Callable[[_T], None]) -> Callable[Concatenate[_T, _P], _R]:
+                return implementation
+
+            return decorator
+
+        return implement_by
+
+    @staticmethod
+    def create_implement_by_no_self() -> Callable[
+        [Callable[_P, _R]],
+        Callable[
+            [Callable[[_T], None]],
+            Callable[Concatenate[_T, _P], _R],
+        ],
+    ]:
+        def implement_by_no_self(
+            m: Callable[_P, _R],
+        ) -> Callable[
+            [Callable[[_T], None]],
+            Callable[Concatenate[_T, _P], _R],
+        ]:
+            def implementation(_self: _T, *args: _P.args, **kwargs: _P.kwargs) -> _R:
+                return m(*args, **kwargs)
+
+            def decorator(_: Callable[[_T], None]) -> Callable[Concatenate[_T, _P], _R]:
+                return implementation
+
+            return decorator
+
+        return implement_by_no_self
+
+
+CRU.add