1 files changed, 92 insertions, 1 deletions

diff --git a/pydis_core/utils/function.py b/pydis_core/utils/function.py
index 7a97027b..911f660d 100644
--- a/pydis_core/utils/function.py
+++ b/pydis_core/utils/function.py
@@ -3,22 +3,113 @@
 from __future__ import annotations
 
 import functools
+import inspect
 import types
 import typing
 from collections.abc import Callable, Sequence, Set
 
-__all__ = ["GlobalNameConflictError", "command_wraps", "update_wrapper_globals"]
+__all__ = [
+    "GlobalNameConflictError",
+    "command_wraps",
+    "get_arg_value",
+    "get_arg_value_wrapper",
+    "get_bound_args",
+    "update_wrapper_globals",
+]
 
 
 if typing.TYPE_CHECKING:
     _P = typing.ParamSpec("_P")
     _R = typing.TypeVar("_R")
 
+Argument = int | str
+BoundArgs = typing.OrderedDict[str, typing.Any]
+Decorator = typing.Callable[[typing.Callable], typing.Callable]
+ArgValGetter = typing.Callable[[BoundArgs], typing.Any]
+
 
 class GlobalNameConflictError(Exception):
     """Raised on a conflict between the globals used to resolve annotations of a wrapped function and its wrapper."""
 
 
+def get_arg_value(name_or_pos: Argument, arguments: BoundArgs) -> typing.Any:
+    """
+    Return a value from `arguments` based on a name or position.
+
+    Arguments:
+        arguments: An ordered mapping of parameter names to argument values.
+    Returns:
+        Value from `arguments` based on a name or position.
+    Raises:
+        TypeError: `name_or_pos` isn't a str or int.
+        ValueError: `name_or_pos` does not match any argument.
+    """
+    if isinstance(name_or_pos, int):
+        # Convert arguments to a tuple to make them indexable.
+        arg_values = tuple(arguments.items())
+        arg_pos = name_or_pos
+
+        try:
+            _name, value = arg_values[arg_pos]
+            return value
+        except IndexError:
+            raise ValueError(f"Argument position {arg_pos} is out of bounds.")
+    elif isinstance(name_or_pos, str):
+        arg_name = name_or_pos
+        try:
+            return arguments[arg_name]
+        except KeyError:
+            raise ValueError(f"Argument {arg_name!r} doesn't exist.")
+    else:
+        raise TypeError("'arg' must either be an int (positional index) or a str (keyword).")
+
+
+def get_arg_value_wrapper(
+    decorator_func: typing.Callable[[ArgValGetter], Decorator],
+    name_or_pos: Argument,
+    func: typing.Callable[[typing.Any], typing.Any] | None = None,
+) -> Decorator:
+    """
+    Call `decorator_func` with the value of the arg at the given name/position.
+
+    Arguments:
+        decorator_func: A function that must accept a callable as a parameter to which it will pass a mapping of
+            parameter names to argument values of the function it's decorating.
+        name_or_pos: The name/position of the arg to get the value from.
+        func: An optional callable which will return a new value given the argument's value.
+
+    Returns:
+        The decorator returned by `decorator_func`.
+    """
+    def wrapper(args: BoundArgs) -> typing.Any:
+        value = get_arg_value(name_or_pos, args)
+        if func:
+            value = func(value)
+        return value
+
+    return decorator_func(wrapper)
+
+
+def get_bound_args(func: typing.Callable, args: tuple, kwargs: dict[str, typing.Any]) -> BoundArgs:
+    """
+    Bind `args` and `kwargs` to `func` and return a mapping of parameter names to argument values.
+
+    Default parameter values are also set.
+
+    Args:
+        args: The arguments to bind to ``func``
+        kwargs: The keyword arguments to bind to ``func``
+        func: The function to bind ``args`` and ``kwargs`` to
+    Returns:
+        A mapping of parameter names to argument values.
+    """
+    sig = inspect.signature(func)
+    bound_args = sig.bind(*args, **kwargs)
+    bound_args.apply_defaults()
+
+    return bound_args.arguments
+
+
 def update_wrapper_globals(
     wrapper: Callable[_P, _R],
     wrapped: Callable[_P, _R],