draft of parameter conversion

this isn't really exactly the right place: we only want to do this in the
IPC version of things, not the lazy.* version, since the lazy.* version
should just have users passing the right things, so this will result in a
bunch of extra useless work. but it's an example of parameter hoisting.

Signed-off-by: Tycho Andersen <tycho@tycho.pizza>

libqtile/command/interface.py

@@ -24,9 +24,11 @@
 
 from __future__ import annotations
 
+import inspect
 import traceback
+import types
 from abc import ABCMeta, abstractmethod
-from typing import TYPE_CHECKING
+from typing import TYPE_CHECKING, get_args, get_origin
 
 from libqtile import ipc
 from libqtile.command.base import CommandError, CommandException, CommandObject, SelectError
@@ -308,13 +310,63 @@ def call(self, data: tuple[list[SelectorType], str, tuple, dict]) -> tuple[int,
             return ERROR, "No such command"
 
         logger.debug("Command: %s(%s, %s)", name, args, kwargs)
-        try:
-            # Check if method is bound
-            if hasattr(cmd, "__self__"):
-                return SUCCESS, cmd(*args, **kwargs)
+
+        def lift_arg(typ, arg):
+            # for stuff like int | None, allow either
+            if get_origin(typ) is types.UnionType:
+                for t in get_args(typ):
+                    if t == types.NoneType:
+                        # special case None? I don't know what this looks like
+                        # coming over IPC
+                        if arg == "":
+                            return None
+                        if arg is None:
+                            return None
+                        continue
+
+                    try:
+                        return lift_arg(t, arg)
+                    except TypeError:
+                        pass
+                # uh oh, we couldn't lift it to anything
+                raise TypeError(f"{arg} is not a {typ}")
+
+            if get_origin(typ) is list:
+                # i am explicitly too lazy to support heterogeneous lists, even
+                # though it would be easy to do here. that would be an awful
+                # user api.
+                for t in get_args(typ):
+                    try:
+                        out = []
+                        for elt in arg:
+                            out.append(lift_arg(t, elt))
+                    except TypeError:
+                        pass
+                    return out
+                # uh oh, we couldn't lift it to anything
+                raise TypeError(f"{arg} is not a {typ}")
+
+            return typ(arg)
+
+        converted_args = []
+        converted_kwargs = dict()
+
+        params = inspect.signature(cmd).parameters
+
+        i = 0
+        for param in params:
+            # a bit of an assumption...
+            if param == "self":
+                converted_args.append(obj)
             else:
-                # If not, pass object as first argument
-                return SUCCESS, cmd(obj, *args, **kwargs)
+                converted_args.append(lift_arg(params[param].annotation, args[i]))
+                i = i + 1
+
+        for k, v in kwargs:
+            converted_kwargs[k] = lift_arg(params[k].annotation, v)
+
+        try:
+            return SUCCESS, cmd(*converted_args, **converted_kwargs)
         except CommandError as err:
             return ERROR, err.args[0]
         except Exception:

test/test_command.py

@@ -88,6 +88,12 @@ def test_layout_filter(manager):
     assert manager.c.get_groups()["a"]["focus"] == "two"
 
 
+@call_config
+def test_param_hoisting(manager):
+    manager.c.widget["groupbox"].set_font(font="sans")
+    manager.c.widget["groupbox"].set_font(font=1)
+
+
 class FakeCommandObject(CommandObject):
     @staticmethod
     @expose_command()