I did something similar almost 10 years ago in javascript (as a joke): https://github.com/Matsemann/Declaraoids

One example, arr.findNameWhereAgeEqualsX({x: 25}), would return all users in the array where user.age == 25.

Not based on LLMs, though. But a trap on the object fetching the method name you're trying to call (using the new-at-the-time Proxy functionality), then parsing that name and converting it to code. Deterministic, but based on rules.