alt Hacker NewsWhat I'm missing:
1. The readme doesn't make it clear what its "float" type is. A double, a decimal, implementation defined. I'm generally not a fan of restricting numbers to what a double can represent, like toml does.
2. It doesn't have a good way to model key-value pair like types such as tagged unions, polymorphic types, or function invocations. Simply allowing a key-value pair as a value (right associative) where the key is a string matching the keys of an object would fix this. Alternatively a function call syntax would fix this, which would also enable tuples as a concept distinct from arrays.
The tagged-union / function-call point is where I keep ending up too. Once a config needs “one of these shapes” or “this thing with these arguments”, data formats grow conventions on top (type: keys, YAML !tags, $ref), and every consumer reimplements them.
I’ve been building Forma (https://forma-lang.com), a small typed Lisp aimed at that zone. Everything is (head args...), so a tagged value and a call are the same syntax, and you declare the vocabulary yourself:
job and backoff are forms you define with typed holes. The checker reports errors at the line you wrote, even after macro expansion. The output is plain JSON (or generated Effect TypeScript, but could target any language), so the app reading it doesn’t embed the language.