@david_chisnall how do you feel about CUE?

@david_chisnall “they’ve added mechanisms for mutating existing things” - what feature in Pkl is this referring to?

@david_chisnall I keep thinking about some kind of "configuration format shebang". Just have a library that you call to read config and it hands you a JSON-like parsed data structure... and have this library have configurable plugins so that the user can install whatever plugin they like.

@mxey

It’s documented under lists. You can modify list elements from earlier, but it’s also generically an imperative language so you can do arbitrary mutations, whereas the early version I looked at was purely declarative.

I really like the way UCL did this, with explicit merge policies, but it had problems in practice because deleting a node and replacing it vs mutating one field were hard to specify, so you often ended up copying more than you needed.

The approach of an imperative language that creates objects against a verifiable schema and then exposes those as a well-defined data model is what I actually want.

@mxey I have never seen it before. But a quick skim suggests that it might be another good option.