[laserbeam]

> 1. Compatibility is a key factor here, so we'd want to go with base-level JSON. I'd prefer being able to have trailing commas in lists, but not enough to make life hard for someone implementing this without access to a JSON5 parser.

This is what I was referring to. This is not json:

> #..meta: format=json, length=270

> The header formats are meant to be very simple key/value pairs that are known by the parser, and not free-form bits of metadata. That's what the "meta" blocks are for. The parsing rules for the header are intentionally very simple.

Exactly my point. That level of flexibility for a .patch format to support another language embedded in it is overwhelming. Keep in mind that you are proposing a textual format, not a binary format. So people will use 3rd party text parsing tools to play with it. And having 2 distinct languages in there makes that annoying and a pain.

[hdjrudni]

How do they reasonable work around that though? If they want the ability to move away from JSON, you have to know that it is JSON before trying to parse it. And then you need to know how much data to read. So I can see why they put those 2 tidbits of info above data block.

Maybe they could have said too bad, JSON for life, we'll never change it. OK. But then you still need the length or a delimiter for the "end of json".