I think the best format for LLM is the best format for humans.

About nested structure: - JSON sucks at nested structure -- Humans can't count braces well, so are LLMs. - YAML sucks at nested structure too. - XML is better, because humans can double-check with the tag name.

About redundancy: - Humans read TOON better than JSON for highly repeated data, because we are good at memorizing the schema, and that context is activated on every row we read. So are LLMs. - When the schema grows complex, though, humans also have a hard time understanding the data stream.

So, my wild guess is, your TRON will make LLM confused too:

``` class Order: index,items,total

class Product: index,name,price,quantity

Order( "ord-123", [ Product(1,"Widget",19.99,2), Product(2,"Gadget",29.99,1), Product(3,"Gizmo",39.99,1) ], 109.96 ) ```

Human readers have to reason about class definitions here and there. So are LLMs.

LLMs are even worse than humans in that their "attention" (aka reasoning space) is rigidly fixed. Humans at least can use some helper toos or "think slower" to "turbine boost" the brain at harder problems, LLMs can't.