A lisp compiler in a voice assistant would seem like an improvement in that the user could define objects and then express the actions to be performed in the same room. But these assistants seem to drop objects between commands making them hard to program conversationally.
I guess a list like language would be ideal and the pauses would be like parentheses
Not to take away from your point (I'd like the magic list too) but to some degree, this can be worked around using Shortcuts. If you use inputs, Siri will prompt for them which is a bit slow but you could even use a dictate text and parse yourself if desired.
Hey Siri
Turn lights on 50 percent
For one hour
Dim over that time
Play music.
I can learn what I need to do; JUST LET ME KNOW THE MAGIC WORDS!