6 files changed, 633 insertions, 119 deletions

diff --git a/tools/cru-py/cru/attr.py b/tools/cru-py/cru/attr.py
index d07cc55..5d4f276 100644
--- a/tools/cru-py/cru/attr.py
+++ b/tools/cru-py/cru/attr.py
@@ -1,8 +1,9 @@
+import copy
 from collections.abc import Callable
-from dataclasses import dataclass
-from types import NoneType
+from dataclasses import dataclass, field
 from typing import Any
-from copy import deepcopy
+
+from .util import CanBeList, TypeSet, L, ListOperations
 
 
 @dataclass
@@ -12,63 +13,243 @@ class CruAttr:
     description: str
 
 
+class _CruAttrVoid:
+    _i = False
+
+    def __init__(self):
+        if self._i:
+            raise ValueError("CruAttrNotSet is a singleton!")
+        self._i = True
+
+    def __copy__(self):
+        return self
+
+
+CRU_ATTR_NOT_SET = _CruAttrVoid()
+CRU_ATTR_USE_DEFAULT = CRU_ATTR_NOT_SET.__copy__()
+
+
+def _is_attr_void(v: Any) -> bool:
+    return isinstance(v, _CruAttrVoid)
+
+
 @dataclass
 class CruAttrDef:
     name: str
-    default_description: str
-    allow_types: None | set[type]
-    allow_none: bool
-    default_value: Any
-    transformer: Callable[[Any], Any] | None
+    description: str
+    default_factory: Callable[[], Any]
+    transformer: Callable[[Any], Any]
     validator: Callable[[Any], None]
 
-    def __init__(self, name: str, default_description: str, *,
-                 allow_types: list[type] | type | None, allow_none: bool, default_value: Any = None,
-                 transformer: Callable[[Any], Any] | None = None,
-                 validator: Callable[[Any], None] | None = None) -> None:
+    def __init__(self, name: str, description: str, default_factory: Callable[[], Any],
+                 transformer: Callable[[Any], Any], validator: Callable[[Any], None]) -> None:
         self.name = name
-        self.default_description = default_description
-        self.default_value = default_value
-        #TODO: CONTINUE TOMORROW
-        if allow_types is None:
-            allow_types = []
-        elif isinstance(allow_types, type):
-            allow_types = [allow_types]
-        else:
-            for t in allow_types:
-                if not isinstance(t, type):
-                    raise TypeError(f"Invalid value of python type : {t}")
-        self.allow_types = set(filter(lambda tt: tt is not NoneType, allow_types))
-        self.allow_none = allow_none
+        self.description = description
+        self.default_factory = default_factory
         self.transformer = transformer
         self.validator = validator
-        self.default_value = self.transform_and_validate(self.default_value)
-        self.default_value = deepcopy(self.default_value)
 
     def transform(self, value: Any) -> Any:
         if self.transformer is not None:
             return self.transformer(value)
         return value
 
-    def validate(self, value: Any, /, override_allow_none: bool | None = None) -> None:
-        allow_none = override_allow_none if override_allow_none is not None else self.allow_none
-        if value is None and not allow_none:
-            raise TypeError(f"None is not allowed!")
-        if len(self.allow_types) != 0 and type(value) not in self.allow_types:
-            raise TypeError(f"Type of {value} is not allowed!")
+    def validate(self, value: Any, /, force_allow_none: bool = False) -> None:
+        if force_allow_none is value is None:
+            return
         if self.validator is not None:
-            return self.validator(value)
-        return None
+            self.validator(value)
 
-    def transform_and_validate(self, value: Any, /, override_allow_none: bool | None = None) -> Any:
+    def transform_and_validate(self, value: Any = CRU_ATTR_USE_DEFAULT, /, force_allow_none: bool = False) -> Any:
         value = self.transform(value)
-        self.validate(value, override_allow_none)
+        self.validate(value, force_allow_none)
         return value
 
-    def make(self, value: Any, description: None | str = None) -> CruAttr:
+    def make_default_value(self) -> Any:
+        return self.transform_and_validate(self.default_factory())
+
+    def adopt(self, attr: CruAttr) -> CruAttr:
+        attr = copy.deepcopy(attr)
+
+        if attr.name is None:
+            attr.name = self.name
+        elif attr.name != self.name:
+            raise ValueError(f"Attr name is not match: {attr.name} != {self.name}")
+
+        if attr.value is CRU_ATTR_NOT_SET:
+            attr.value = self.make_default_value()
+        else:
+            attr.value = self.transform_and_validate(attr.value)
+
+        if attr.description is None:
+            attr.description = self.description
+
+        return attr
+
+    def make(self, value: Any = CRU_ATTR_USE_DEFAULT, description: None | str = None) -> CruAttr:
+        value = self.default_factory() if _is_attr_void(value) else value
+        value = self.default_factory() if value is CRU_ATTR_USE_DEFAULT else value
         value = self.transform_and_validate(value)
-        return CruAttr(self.name, value if value is not None else deepcopy(self.default_value),
-                       description if description is not None else self.default_description)
+        return CruAttr(self.name, value,
+                       description if description is not None else self.description)
+
+
+@dataclass
+class CruAttrDefBuilder:
+    name: str
+    description: str
+    types: CanBeList[type] = field(default=None)
+    allow_none: bool = field(default=True)
+    default: Any = field(default=CRU_ATTR_NOT_SET)
+    default_factory: Callable[[], Any] | None = field(default=None)
+    auto_list: bool = field(default=False)
+    transformers: list[Callable[[Any], Any]] = field(default_factory=list)
+    validators: list[Callable[[Any], None]] = field(default_factory=list)
+    override_transformer: Callable[[Any], Any] | None = field(default=None)
+    override_validator: Callable[[Any], None] | None = field(default=None)
+
+    build_hook: Callable[[CruAttrDef], None] | None = field(default=None)
+
+    def __init__(self, name: str, description: str) -> None:
+        super().__init__()
+        self.name = name
+        self.description = description
+
+    def auto_adjust_default(self) -> "CruAttrDefBuilder":
+        if self.default is not CRU_ATTR_NOT_SET and self.default is not None:
+            return self
+        if self.allow_none and _is_attr_void(self.default):
+            self.default = None
+        if not self.allow_none and self.default is None:
+            self.default = CRU_ATTR_NOT_SET
+        if self.auto_list and not self.allow_none:
+            self.default = []
+
+    def with_name(self, name: str) -> "CruAttrDefBuilder":
+        self.name = name
+        return self
+
+    def with_description(self, default_description: str) -> "CruAttrDefBuilder":
+        self.description = default_description
+        return self
+
+    def with_default(self, default: Any, is_factory: bool = False,
+                     reserve_if_not_set: bool = False) -> "CruAttrDefBuilder":
+        if is_factory:
+            self.default_factory = default
+        else:
+            if _is_attr_void(default) and reserve_if_not_set:
+                return self
+            else:
+                self.default = default
+        return self
+
+    def with_default_factory(self, default_factory: Callable[[], Any]) -> "CruAttrDefBuilder":
+        return self.with_default(default_factory, is_factory=True)
+
+    def with_types(self, allowed_types: CanBeList[type], default: Any = CRU_ATTR_NOT_SET) -> "CruAttrDefBuilder":
+        self.types = allowed_types
+        if _is_attr_void(default):
+            self.default = default
+        return self
+
+    def with_allow_none(self, allow_none: bool, default: Any = CRU_ATTR_NOT_SET) -> "CruAttrDefBuilder":
+        self.allow_none = allow_none
+        if _is_attr_void(default):
+            self.default = default
+        return self
+
+    def with_optional(self, default: Any = CRU_ATTR_NOT_SET) -> "CruAttrDefBuilder":
+        return self.with_allow_none(True, default)
+
+    def with_required(self, default: Any = CRU_ATTR_NOT_SET) -> "CruAttrDefBuilder":
+        return self.with_allow_none(False, default)
+
+    def with_constraint(self, required: bool, allowed_types: CanBeList[type] = None, /,
+                        default: Any = CRU_ATTR_NOT_SET, auto_list=False, *, default_is_factory: bool = False,
+                        default_reserve_if_not_set: bool = True) -> "CruAttrDefBuilder":
+        return (self.with_allow_none(required).with_types(allowed_types).with_auto_list(auto_list).
+                with_default(default, default_is_factory, default_reserve_if_not_set))
+
+    def with_auto_list(self, transform_auto_list: bool = True) -> "CruAttrDefBuilder":
+        self.auto_list = transform_auto_list
+        return self
+
+    def add_transformer(self, transformer: Callable[[Any], Any] | None) -> "CruAttrDefBuilder":
+        if transformer is not None:
+            self.transformers.append(transformer)
+        return self
+
+    def clear_transformers(self) -> "CruAttrDefBuilder":
+        self.transformers.clear()
+        return self
+
+    def add_validator(self, validator: Callable[[Any], None] | None) -> "CruAttrDefBuilder":
+        if validator is not None:
+            self.validators.append(validator)
+        return self
+
+    def clear_validators(self) -> "CruAttrDefBuilder":
+        self.validators.clear()
+        return self
+
+    def with_override_transformer(self, override_transformer: Callable[[Any], Any] | None) -> "CruAttrDefBuilder":
+        self.override_transformer = override_transformer
+        return self
+
+    def with_override_validator(self, override_validator: Callable[[Any], None] | None) -> "CruAttrDefBuilder":
+        self.override_validator = override_validator
+        return self
+
+    def is_valid(self) -> tuple[bool, str]:
+        if not isinstance(self.name, str):
+            return False, "Name must be a string!"
+        if not isinstance(self.description, str):
+            return False, "Default description must be a string!"
+        if not self.allow_none and self.default is None and self.default_factory is None:
+            return False, "Default must be set if allow_none is False!"
+
+    @staticmethod
+    def _build(b: "CruAttrDefBuilder", auto_adjust_default: bool = True) -> CruAttrDef:
+        if auto_adjust_default:
+            b.auto_adjust_default()
+
+        valid, err = b.is_valid()
+        if not valid: raise ValueError(err)
+
+        def composed_transformer(v: Any):
+            if b.auto_list:
+                v = L.make(v)
+            for t in b.transformers:
+                v = t(v)
+            return v
+
+        type_set = TypeSet(b.types)
+
+        def composed_validator(v: Any):
+            if b.auto_list:
+                type_set.check_value_list(v, allow_none=b.allow_none)
+                ListOperations.foreach(v, *b.validators)
+            else:
+                type_set.check_value(v, allow_none=b.allow_none)
+                for vl in b.validators: vl(v)
+
+        validator = b.override_validator or composed_validator
+        transformer = b.override_transformer or composed_transformer
+
+        default_factory = b.default_factory
+        if b.default_factory is None:
+            default_factory = lambda: copy.deepcopy(b.default)
+        validator(default_factory())
+
+        d = CruAttrDef(b.name, b.description, default_factory, transformer, validator)
+        if b.build_hook: b.build_hook(d)
+        return d
+
+    def build(self, auto_adjust_default=True) -> CruAttrDef:
+        c = copy.deepcopy(self)
+        self.build_hook = None
+        return CruAttrDefBuilder._build(c, auto_adjust_default)
 
 
 class CruAttrDefRegistry:
@@ -86,34 +267,10 @@ class CruAttrDefRegistry:
                 raise ValueError(f"Attribute {def_.name} already exists!")
         self._def_list.append(def_)
 
-    def register_with(self, name: str, default_description: str, *,
-                      allow_types: list[type] | type | None, allow_none: bool,
-                      default_value: Any = None,
-                      transformer: Callable[[Any], Any] | None = None,
-                      validator: Callable[[Any], None] | None = None
-                      ) -> CruAttrDef:
-        def_ = CruAttrDef(name, default_description, default_value=default_value, allow_types=allow_types,
-                          allow_none=allow_none, transformer=transformer, validator=validator)
-        self.register(def_)
-        return def_
-
-    def register_required(self, name: str, default_description: str, *,
-                      allow_types: list[type] | type | None,
-                      default_value: Any = None,
-                      transformer: Callable[[Any], Any] | None = None,
-                      validator: Callable[[Any], None] | None = None
-                      ) -> CruAttrDef:
-        return self.register_with(name, default_description, default_value=default_value, allow_types=allow_types,
-                          allow_none=False, transformer=transformer, validator=validator)
-
-    def register_optional(self, name: str, default_description: str, *,
-                      allow_types: list[type] | type | None,
-                      default_value: Any = None,
-                      transformer: Callable[[Any], Any] | None = None,
-                      validator: Callable[[Any], None] | None = None
-                      ) -> CruAttrDef:
-        return self.register_with(name, default_description, default_value=default_value, allow_types=allow_types,
-                          allow_none=True, transformer=transformer, validator=validator)
+    def make_builder(self, name: str, default_description: str) -> CruAttrDefBuilder:
+        b = CruAttrDefBuilder(name, default_description)
+        b.build_hook = lambda a: self.register(a)
+        return b
 
     def get_item_optional(self, name: str) -> CruAttrDef | None:
         for i in self._def_list:
@@ -121,5 +278,67 @@ class CruAttrDefRegistry:
                 return i
         return None
 
-    def __getitem__(self, item) -> CruAttrDef | None:
-        return self.get_item_optional(item)
+
+class CruAttrTable:
+    def __init__(self, registry: CruAttrDefRegistry) -> None:
+        self._registry: CruAttrDefRegistry = registry
+        self._attrs: list[CruAttr] = []
+
+    def get_attr_or(self, name: str, fallback: Any = None) -> CruAttr | Any:
+        for a in self._attrs:
+            if a.name == name:
+                return a
+        return fallback
+
+    def get_attr(self, name) -> CruAttr:
+        a = self.get_attr_or(name, None)
+        if a is None:
+            raise KeyError(f"Attribute {name} not found!")
+        return a
+
+    def get_value_or(self, name: str, fallback: Any = None) -> Any:
+        a = self.get_attr_or(name, None)
+        if a is None:
+            return fallback
+        return a.value
+
+    def get_value(self, name: str) -> Any:
+        a = self.get_attr(name)
+        return a.value
+
+    def get_def_or(self, name: str, fallback: Any = None) -> CruAttrDef | Any:
+        d = self._registry.get_item_optional(name)
+        return d if d is not None else fallback
+
+    def get_def(self, name: str) -> CruAttrDef:
+        d = self._registry.get_item_optional(name)
+        if d is None:
+            raise KeyError(f"Attribute definition {name} not found!")
+        return d
+
+    def _check_already_exist(self, name: str) -> None:
+        if name in self:
+            raise KeyError(f"Attribute {name} already exists!")
+
+    def add_attr(self, attr: CruAttr) -> CruAttr:
+        self._check_already_exist(attr.name)
+        d = self.get_def(attr.name)
+        attr = d.adopt(attr)
+        self._attrs.append(attr)
+        return attr
+
+    def add(self, name: str, value: Any = CRU_ATTR_USE_DEFAULT, /, description: str | None = None) -> CruAttr:
+        self._check_already_exist(name)
+        d = self.get_def(name)
+        attr = d.make(value, description or d.description)
+        self._attrs.append(attr)
+        return attr
+
+    def remove(self, name: str, /, allow_absense: bool = True) -> None:
+        l = [a for a in self._attrs if a.name == name]
+        if len(l) != len(self._attrs) and not allow_absense:
+            raise KeyError(f"Attribute {name} not found!")
+        self._attrs = l
+
+    def __contains__(self, name):
+        return any(a.name == name for a in self._attrs)
diff --git a/tools/cru-py/cru/excp.py b/tools/cru-py/cru/excp.py
index 5a5871b..6734140 100644
--- a/tools/cru-py/cru/excp.py
+++ b/tools/cru-py/cru/excp.py
@@ -1,63 +1,41 @@
-from collections.abc import Callable
-from dataclasses import dataclass
-from types import NoneType
 from typing import Any
 
-from cru.attr import CruAttrDefRegistry
+from .attr import CruAttrDefRegistry, CRU_ATTR_USE_DEFAULT, CruAttr, CruAttrTable
+from .util import CanBeList
 
 CRU_EXCEPTION_ATTR_DEF_REGISTRY = CruAttrDefRegistry()
-
-
-class CruException(Exception):
-    @staticmethod
-    def transform_inner(inner: Exception | list[Exception] | None):
-        if inner is None:
-            return None
-        if isinstance(inner, Exception):
-            return [inner]
-        if isinstance(inner, list):
-            return inner
-
-    @staticmethod
-    def validate_inner(inner: list[Exception]):
-        for i in inner:
-            if not isinstance(i, Exception):
-                raise TypeError(f"Invalid inner exception: {i}")
-
-    MESSAGE_DEF = CRU_EXCEPTION_ATTR_DEF_REGISTRY.register_required("message", "Message describing the exception.",
-                                                                allow_types=str, default_value="")
-    INNER_DEF = CRU_EXCEPTION_ATTR_DEF_REGISTRY.register_required("inner", "Inner exception.",
-                                                  allow_types=list, default_value=[],
-                                                  transformer=transform_inner, validator=validate_inner)
-    INTERNAL_DEF = CRU_EXCEPTION_ATTR_DEF_REGISTRY.register_required("internal",
-                                                  "True if the exception is caused by wrong internal logic. False if it is caused by user's wrong input.",
-                                                  allow_types=bool, default_value=False)
-    CRU_EXCEPTION_ATTR_DEF_REGISTRY.register_optional("name", "Name of the object that causes the exception.",
-                                                  allow_types=str)
-    CRU_EXCEPTION_ATTR_DEF_REGISTRY.register_optional("value", "Value that causes the exception.",
-                                                  allow_types=[])
-    CRU_EXCEPTION_ATTR_DEF_REGISTRY.register_with("path", "Path that causes the exception.",)
-    CRU_EXCEPTION_ATTR_DEF_REGISTRY.register_with("type", "Python type related to the exception.")
-
+_REGISTRY = CRU_EXCEPTION_ATTR_DEF_REGISTRY
+
+
+class CruException(Exception, CruAttrTable):
+    MESSAGE_KEY = "message"
+    INNER_KEY = "inner"
+    INTERNAL_KEY = "internal"
+    NAME_KEY = "name"
+    VALUE_KEY = "value"
+    PATH_KEY = "path"
+    TYPE_KEY = "type_"
+
+    _REGISTRY.make_builder(MESSAGE_KEY, "Message describing the exception.").with_constraint(True, str,
+                                                                                             "").build()
+    _REGISTRY.make_builder("inner", "Inner exception.").with_constraint(True, Exception,
+                                                                        auto_list=True).build()
+    _REGISTRY.make_builder("internal",
+                           "True if the exception is caused by wrong internal logic. False if it is caused by user's wrong input.").with_constraint(
+        True, bool, False).build()
+    _REGISTRY.make_builder(NAME_KEY, "Name of the object that causes the exception.").with_types(str).build()
+    _REGISTRY.make_builder(VALUE_KEY, "Value that causes the exception.").build()
+    _REGISTRY.make_builder(PATH_KEY, "Path that causes the exception.").with_types(str).build()
+    _REGISTRY.make_builder(TYPE_KEY, "Python type related to the exception.").with_types(type).build()
+
+    # TODO: CONTINUE HERE TOMORROW!
     def __init__(self, message: str, *args,
-                 inner: Exception | list[Exception] | None = None,
-                 internal: bool = False,
-                 name: str | None = None,
-                 value: Any | None = None,
-                 path: str | None = None,
-                 type_: type | None = None,
                  init_attrs: dict[str, Any] | None = None,
                  attrs: dict[str, Any] | None = None, **kwargs) -> None:
         super().__init__(message, *args)
 
         self._attrs = {
             CruException.MESSAGE_KEY: message,
-            CruException.INTERNAL_KEY: internal,
-            CruException.INNER_KEY: inner,
-            CruException.NAME_KEY: name,
-            CruException.VALUE_KEY: value,
-            CruException.PATH_KEY: path,
-            CruException.TYPE_KEY: type_,
         }
         if init_attrs is not None:
             self._attrs.update(init_attrs)
diff --git a/tools/cru-py/cru/util/__init__.py b/tools/cru-py/cru/util/__init__.py
new file mode 100644
index 0000000..83ab9f3
--- /dev/null
+++ b/tools/cru-py/cru/util/__init__.py
@@ -0,0 +1,14 @@
+from ._func import CruFunction, MetaFunction, RawFunctions, WrappedFunctions, PLACEHOLDER
+from ._list import CruList, ListOperations, CanBeList
+from ._type import TypeSet
+
+F = CruFunction
+WF = WrappedFunctions
+L = CruList
+
+__all__ = [
+    "CruFunction", "MetaFunction", "RawFunctions", "WrappedFunctions", "PLACEHOLDER",
+    "CruList", "ListOperations", "CanBeList",
+    "TypeSet",
+    "F", "WF", "L",
+]
diff --git a/tools/cru-py/cru/util/_func.py b/tools/cru-py/cru/util/_func.py
new file mode 100644
index 0000000..5fb49a9
--- /dev/null
+++ b/tools/cru-py/cru/util/_func.py
@@ -0,0 +1,150 @@
+from collections.abc import Callable, Iterable
+from typing import TypeVar, Any, ParamSpec
+
+from ._list import ListOperations, CruList
+
+T = TypeVar("T")
+R = TypeVar("R")
+R1 = TypeVar("R1")
+P = ParamSpec("P")
+P1 = ParamSpec("P1")
+
+
+class _Placeholder:
+    pass
+
+
+PLACEHOLDER = _Placeholder()
+
+
+class RawFunctions:
+    @staticmethod
+    def ignore(*_v, **_kwargs) -> None:
+        return None
+
+    @staticmethod
+    def true_(*_v, **_kwargs) -> True:
+        return True
+
+    @staticmethod
+    def false_(*_v, **_kwargs) -> False:
+        return False
+
+    @staticmethod
+    def i_dont_care(r: T, *_v, **_kwargs) -> T:
+        return r
+
+    @staticmethod
+    def identity(v: T) -> T:
+        return v
+
+    @staticmethod
+    def equal(a: Any, b: Any) -> bool:
+        return a == b
+
+    @staticmethod
+    def not_equal(a: Any, b: Any) -> bool:
+        return a != b
+
+    @staticmethod
+    def not_(v):
+        return not v
+
+
+class MetaFunction:
+    @staticmethod
+    def bind(f: Callable[P, R], *bind_args, **bind_kwargs) -> Callable[P1, R1]:
+        def bound(*args, **kwargs):
+            popped = 0
+            real_args = []
+            for a in bind_args:
+                if isinstance(a, _Placeholder):
+                    real_args.append(args[popped])
+                    popped += 1
+                else:
+                    real_args.append(a)
+            real_args.extend(args[popped:])
+            return f(*real_args, **(bind_kwargs | kwargs))
+
+        return bound
+
+    @staticmethod
+    def chain(*fs: Callable) -> Callable:
+        if len(fs) == 0:
+            raise ValueError("At least one function is required!")
+        rf = fs[0]
+        for f in fs[1:]:
+            def n(*args, **kwargs):
+                r = rf(*args, **kwargs)
+                r = r if isinstance(r, tuple) else (r,)
+                return f(*r)
+
+            rf = n
+        return rf
+
+    @staticmethod
+    def chain_single(f: Callable[P, R], f1: Callable[P1, R1], *bind_args, **bind_kwargs) -> \
+            Callable[
+                P, R1]:
+        return MetaFunction.chain(f, MetaFunction.bind(f1, *bind_args, **bind_kwargs))
+
+    convert_r = chain_single
+
+    @staticmethod
+    def neg(f: Callable[P, bool]) -> Callable[P, bool]:
+        return MetaFunction.convert_r(f, RawFunctions.not_)
+
+
+# Advanced Function Wrapper
+class CruFunction:
+    def __init__(self, f):
+        self._f = f
+
+    @property
+    def f(self) -> Callable:
+        return self._f
+
+    def bind(self, *bind_args, **bind_kwargs) -> "CruFunction":
+        self._f = MetaFunction.bind(self._f, *bind_args, **bind_kwargs)
+        return self
+
+    def chain(self, *fs: Callable) -> "CruFunction":
+        self._f = MetaFunction.chain(self._f, *fs)
+        return self
+
+    def chain_single(self, f: Callable[P, R], f1: Callable[P1, R1], *bind_args,
+                     **bind_kwargs) -> "CruFunction":
+        self._f = MetaFunction.chain_single(self._f, f, f1, *bind_args, **bind_kwargs)
+        return self
+
+    def convert_r(self, f: Callable[P, R], f1: Callable[P1, R1], *bind_args,
+                  **bind_kwargs) -> "CruFunction":
+        self._f = MetaFunction.convert_r(self._f, f, f1, *bind_args, **bind_kwargs)
+        return self
+
+    def neg(self) -> "CruFunction":
+        self._f = MetaFunction.neg(self._f)
+        return self
+
+    def __call__(self, *args, **kwargs):
+        return self._f(*args, **kwargs)
+
+    def list_transform(self, l: Iterable[T]) -> CruList[T]:
+        return CruList(l).transform(self)
+
+    def list_all(self, l: Iterable[T]) -> bool:
+        return ListOperations.all(l, self)
+
+    def list_any(self, l: Iterable[T]) -> bool:
+        return ListOperations.any(l, self)
+
+    def list_remove_all_if(self, l: Iterable[T]) -> CruList[T]:
+        return CruList(ListOperations.remove_all_if(l, self))
+
+
+class WrappedFunctions:
+    identity = CruFunction(RawFunctions.identity)
+    ignore = CruFunction(RawFunctions.ignore)
+    equal = CruFunction(RawFunctions.equal)
+    not_equal = CruFunction(RawFunctions.not_equal)
+    not_ = CruFunction(RawFunctions.not_)
diff --git a/tools/cru-py/cru/util/_list.py b/tools/cru-py/cru/util/_list.py
new file mode 100644
index 0000000..3b4cb28
--- /dev/null
+++ b/tools/cru-py/cru/util/_list.py
@@ -0,0 +1,111 @@
+from collections.abc import Iterable, Callable
+from typing import TypeVar, ParamSpec, Any, Generic
+
+T = TypeVar("T")
+R = TypeVar("R")
+P = ParamSpec("P")
+
+CanBeList = T | Iterable[T] | None
+
+
+class ListOperations:
+
+    @staticmethod
+    def foreach(l: Iterable[T], *f: Callable[[T], None] | None) -> None:
+        if len(f) == 0: return
+        for v in l:
+            for f_ in f:
+                if f_ is not None:
+                    f_(v)
+
+    @staticmethod
+    def transform(l: Iterable[T], *f: Callable | None) -> list[R]:
+        r = []
+        for v in l:
+            for f_ in f:
+                if f_ is not None:
+                    v = f_(v)
+            r.append(v)
+        return r
+
+    @staticmethod
+    def transform_if(l: Iterable[T], f: Callable[[T], R] | None, p: Callable[[T], bool] | None) -> list[R]:
+        return [(f(v) if f else v) for v in l if (p(v) if p else True)]
+
+    @staticmethod
+    def all(l: Iterable[T], *p: Callable[[T], bool] | None) -> bool:
+        if len(p) == 0 or all(v is None for v in p):
+            raise ValueError("At least one predicate is required!")
+        for v in l:
+            for p_ in p:
+                if p_ is not None and not p_(v): return False
+        return True
+
+    @staticmethod
+    def all_is_instance(l: Iterable[T], *t: type) -> bool:
+        return all(type(v) in t for v in l)
+
+    @staticmethod
+    def any(l: Iterable[T], *p: Callable[[T], bool] | None) -> bool:
+        if len(p) == 0 or all(v is None for v in p):
+            raise ValueError("At least one predicate is required!")
+        for v in l:
+            for p_ in p:
+                if p_ is not None and p_(v): return True
+        return False
+
+    @staticmethod
+    def make(v: CanBeList[T], /, none_to_empty_list: bool = True) -> list[T]:
+        if v is None and none_to_empty_list: return []
+        return v if isinstance(v, Iterable) else [v]
+
+    @staticmethod
+    def remove_all_if(l: Iterable[T], *p: Callable[[], bool] | None) -> list[T]:
+        def stay(v):
+            for p_ in p:
+                if p_ is not None and p_(): return False
+            return True
+
+        return [v for v in l if stay(v)]
+
+    @staticmethod
+    def remove_all_value(l: Iterable[T], *r) -> list[T]:
+        return [v for v in l if v not in r]
+
+    @staticmethod
+    def replace_all_value(l: Iterable[T], old_value: Any, new_value: R) -> list[T | R]:
+        return [new_value if v == old_value else v for v in l]
+
+
+class CruList(list, Generic[T]):
+
+    def foreach(self, *f: Callable[[T], None] | None) -> None:
+        ListOperations.foreach(self, *f)
+
+    def transform(self, *f: Callable[[T], R] | None) -> "CruList"[R]:
+        return CruList(ListOperations.transform(self, *f))
+
+    def transform_if(self, f: Callable[[T], R] | None, p: Callable[[T], bool] | None) -> "CruList"[R]:
+        return CruList(ListOperations.transform_if(self, f, p))
+
+    def all(self, *p: Callable[[T], bool] | None) -> bool:
+        return ListOperations.all(self, *p)
+
+    def all_is_instance(self, *t: type) -> bool:
+        return ListOperations.all_is_instance(self, *t)
+
+    def any(self, *p: Callable[[T], bool] | None) -> bool:
+        return ListOperations.any(self, *p)
+
+    def remove_all_if(self, *p: Callable[[]]) -> "CruList"[T]:
+        return CruList(ListOperations.remove_all_if(self, *p))
+
+    def remove_all_value(self, *r) -> "CruList"[T]:
+        return CruList(ListOperations.remove_all_value(self, *r))
+
+    def replace_all_value(self, old_value: Any, new_value: R) -> "CruList"[T | R]:
+        return CruList(ListOperations.replace_all_value(self, old_value, new_value))
+
+    @staticmethod
+    def make(l: CanBeList[T]) -> "CruList"[T]:
+        return CruList(ListOperations.make(l))
diff --git a/tools/cru-py/cru/util/_type.py b/tools/cru-py/cru/util/_type.py
new file mode 100644
index 0000000..dc50def
--- /dev/null
+++ b/tools/cru-py/cru/util/_type.py
@@ -0,0 +1,42 @@
+from types import NoneType
+from typing import Any
+
+from ._list import CanBeList, CruList
+
+DEFAULT_NONE_ERR = ValueError
+DEFAULT_NONE_ERR_MSG = "None is not allowed here."
+DEFAULT_TYPE_ERR = ValueError
+DEFAULT_TYPE_ERR_MSG = "Type of object is not allowed here."
+
+
+class TypeSet(set[type]):
+    def __init__(self, *l: type):
+        l = CruList.make(l).remove_all_value(None, NoneType)
+        if not l.all_is_instance(type):
+            raise TypeError("t must be a type or None.")
+        super().__init__(l)
+
+    def check_value(self, v: Any, /, allow_none: bool, empty_allow_all: bool = True, *,
+                    none_err: type[Exception] = DEFAULT_NONE_ERR,
+                    none_err_msg: str = DEFAULT_NONE_ERR_MSG,
+                    type_err: type[Exception] = DEFAULT_TYPE_ERR,
+                    type_err_msg: str = DEFAULT_TYPE_ERR_MSG) -> None:
+        if v is None:
+            if allow_none:
+                return
+            else:
+                raise none_err(none_err_msg)
+        if len(self) == 0 and empty_allow_all:
+            return
+        if type(v) not in self:
+            raise type_err(type_err_msg)
+
+    def check_value_list(self, l: CanBeList, /, allow_none: bool, empty_allow_all: bool = True, *,
+                         none_err: type[Exception] = DEFAULT_NONE_ERR,
+                         none_err_msg: str = DEFAULT_NONE_ERR_MSG,
+                         type_err: type[Exception] = DEFAULT_TYPE_ERR,
+                         type_err_msg: str = DEFAULT_TYPE_ERR_MSG) -> None:
+        l = CruList.make(l)
+        for v in l:
+            self.check_value(v, allow_none, empty_allow_all, none_err=none_err, none_err_msg=none_err_msg,
+                             type_err=type_err, type_err_msg=type_err_msg)