Dynamically allocate selection commands

I'm not going to lie, this is pretty cool. Last week, I made the fomod
selection logic into its own controller so we could re-use the UI. As
a consequence, we were no longer able to use `<index>` to change fomod
selections, and were stuck using the cumbersome `select <index>`.

It's also worth mentioning here that something like this will not be
allowed (obviously):

    def 0():
        # function named after a number?!

Make the fomod controller create a method named after an integer for
each index associated with a possible fomod selection. Executing the
command will toggle the associated fomod selection.

To top it all off, they get populated into the help menu with a
description named after the option they will change. This can get kind
of long depending on the mod, but it keeps things so that the UI doesn't
have to know anything about the controller, and the controller doesn't
have to know anything about the UI.

ammo/fomod_controller.py

@@ -1,6 +1,7 @@
 #!/usr/bin/env python3
 import os
 import shutil
+from functools import partial
 from pathlib import Path
 from xml.etree import ElementTree
 from functools import reduce
@@ -29,6 +30,7 @@ def __init__(self, mod: Mod):
         self.page = self.steps[self.visible_pages[self.page_index]]
         self.selection = self.page["type"].lower()
         self.do_exit = False
+        self._populate_index_commands()
 
     def __str__(self) -> str:
         num_pages = len(self.visible_pages)
@@ -69,8 +71,31 @@ def _post_exec(self) -> bool:
 
         self.page = self.steps[self.visible_pages[self.page_index]]
         self.selection = self.page["type"].lower()
+        self._populate_index_commands()
         return False
 
+
+    def _populate_index_commands(self):
+        """
+        Hack to get dynamically allocated methods which are
+        named after numbers, one for each selectable option.
+        """
+        # Remove all attributes that are numbers
+        for i in list(self.__dict__.keys()):
+            try:
+                int(i)
+                del self.__dict__[i]
+            except ValueError:
+                pass
+        for i in range(len(self.page["plugins"])):
+            setattr(
+                self,
+                str(i),
+                lambda self, i=i: self._select(i)
+            )
+            self.__dict__[str(i)].__doc__ = f"Toggle {self.page['plugins'][i]['name']}"
+
+
     def _normalize(self, destination: Path, dest_prefix: Path) -> Path:
         """
         Prevent folders with the same name but different case
@@ -387,17 +412,6 @@ def _install_files(self, selected_nodes: list):
 
         self.mod.has_data_dir = True
 
-    def select(self, index: int):
-        """
-        Toggle state
-        """
-        if index < 0 or index > len(self.page["plugins"]):
-            raise Warning(
-                f"Expected 0 through {len(self.page['plugins']) - 1} (inclusive)"
-            )
-
-        self._select(index)
-
     def b(self):
         """
         Return to the previous page

ammo/ui.py

@@ -100,9 +100,14 @@ def populate_commands(self):
             if not callable(attribute):
                 continue
 
-            # attribute is a bound method which is transient.
-            # Get the actual function associated with it.
-            func = attribute.__func__
+            if hasattr(attribute, "__func__"):
+                # attribute is a bound method (which is transient).
+                # Get the actual function associated with it instead
+                # of a descriptor.
+                func = attribute.__func__
+            else:
+                # lambdas
+                func = attribute
 
             signature = inspect.signature(func)
             type_hints = typing.get_type_hints(func)
@@ -111,6 +116,7 @@ def populate_commands(self):
             args = []
             for param in parameters:
                 required = False
+                description = ""
                 if param.default == param.empty:
                     # The argument did not have a default value set.