In my experience LLMs are good at picking up syntax from the context. Recently I used Cursor with an in-house developed language and it was able to get almost

In my experience LLMs are good at picking up syntax from the context. Recently I used Cursor with an in-house developed language and it was able to get almost perfect completions upon seeing ~100 lines of context. Not all LLMs are equally good at this: Gemini seems to be particularly resistant to adapting to a new syntax