A non dertermistic programing language, which options to drop down into JavaScript or even C if you need to specify certain behaviors.
I'd need to be much better at this though.
For example, Claude can fluently generate Bevy code as of the training cutoff date, and there's no way there's enough training data on the web to explain this. There's an agent somewhere in a compile test loop generating Bevy examples.
A custom LLM language could have fine grained fuzzing, mocking, concurrent calling, memoization and other features that allow LLMs to generate and debug synthetic code more effectively.
If that works, there's a pathway to a novel language having higher quality training data than even Python.
I’ve thought about this and arrived at a rough sketch.
The first principle is that models like ChatGPT do not execute programs; they transform context. Because of that, a language designed specifically for LLMs would likely not be imperative (do X, then Y), state-mutating, or instruction-step driven. Instead, it would be declarative and context-transforming, with its primary operation being the propagation of semantic constraints. The core abstraction in such a language would be the context, not the variable. In conventional programming languages, variables hold values and functions map inputs to outputs. In a ChatGPT-native language, the context itself would be the primary object, continuously reshaped by constraints. The atomic unit would therefore be a semantic constraint, not a value or instruction.
An important consequence of this is that types would be semantic rather than numeric or structural. Instead of types like number, string, bool, you might have types such as explanation, argument, analogy, counterexample, formal_definition.
These types would constrain what kind of text may follow, rather than how data is stored or laid out in memory. In other words, the language would shape meaning and allowable continuations, not execution paths. An example:
@iterate: refine explanation until clarity ≥ expert_threshold
You could also work backwards from this paper: https://arxiv.org/abs/2512.18470
I'm imagining something like.
"Hi Ralph, I've already coded a function called GetWeather in JS, it returns weather data in JSON can you build a UI around it. Adjust the UI overtime"
At runtime modify the application with improvements, say all of a sudden we're getting air quality data in the JSON tool, the Ralph loop will notice, and update the application.
The Arxiv paper is cool, but I don't think I can realistically build this solo. It's more of a project for a full team.
I wrote this custom language. It's on Github, but the example code that would have been available would be very limited.
I gave it two inputs -- the original bash script and an example of my pipeline language (unrelated jobs).
The code it gave me was syntactically correct, and was really close to the final version. I didn't have to edit very much to get the code exactly where I wanted it.
This is to say -- if a novel language is somewhat similar to an existing syntax, the LLM will be surprisingly good at writing it.