schema VS edn

Plumatic schema (https://github.com/plumatic/schema) , or friends I might be wrong, but I think schema might make more sense to you coming from the F# world (might be wrong)

This one? I didn't. I hear good things about it, and it's reached a point of maturity, being widely used in production.

Uhhh spec has existed for a long time and before that, schema Nowadays we also have the excellent malli. If his codebase is full of functions where the shape of the data isn’t obvious, isn’t documented and isn’t specified in a specific/schema, that’s on him and his bad coding practices and really no different from passing data in other dynamic languages. A class by itself (without additional effort) only gives you field names.

I don't understand this reputation either. There are very large systems built on other Lisps. For example, Emacs has a massive amount of Elisp. Elisp is much more primitive than Clojure, and traditionally libraries don't use e.g. data schemas [1] as runtime contracts for data.

Obviously, once a system built on top of a dynamic language grows beyond certain threshold, you need to be very disciplined as there are no static types to ensure some degree of correctness.

[1] https://github.com/plumatic/schema

Try to learn a schema library early, like Malli or Prismatic Schema. Do not mistook them as "static-typing" things - it's more for data validation and coercion than "security that things will get the right typing information". The idea to learn them early is how you'll shape future code: validating all "output data" first, them using that data inside your program without "defensive programming" like checking every time if a specific value on a map is nil, etc

In Clojure, declarative data specifications for validation and generation are also very mainstream. Schema was first out the door, Clojure Spec is the most popular library, while malli is gaining popularity fast at the moment.

> was utterly surprised how no one ever apparently has thought to create a configuration/templating system that's basically a fancy library on top of Scheme.

There's Clojure's extensible data notation: https://github.com/edn-format/edn

A thin language layer around edn/datalog, the query language

EDN (Extensible Data Notation) is a subset of Clojure: https://github.com/edn-format/edn

It is:

- Streamable

- Extensible

- Whitespace-insensitive, but there are formatting conventions for readability

To begin with, EDN is somewhat like the JSON of Clojure. And regarding the code is data/data is code nature of Clojure, it is Clojure. It doesn't have some of the vagaries of JSON, and it is also extensible.

Alien is not a reason something is bad, just that's it's unusual. JSON was a bit alien when it first arrived as well, as everyone was used to XML at the time.

`{num 5, val 4}` looks fine to me, but we can do even better! We already know objects/maps are always in pairs, so we don't really need that comma either. Just do `{num 5 val 4}` and we save yet another unnecessary characters.

Of course, I didn't come up with this format myself, what I actually want JSON to be is EDN (https://github.com/edn-format/edn) which is a standalone format but also directly used in Clojure, so it already exists inside a programming language and works very well. There keys are strings though, so you example would end up being `{"num" 5 "val" 5 "person" var}`, where commas are optional.

I just checked out the spec, and it gets pretty ugly in the Table section. A lot of the json examples are both shorter and IMO more precise. Stuff that’s not allowed with [table] is allowed with [[table]], and it’s confusing to understand what level of depth I’m at.

I’ll take edn over any of “em. https://github.com/edn-format/edn

As XT is written in Clojure and it natively supports Clojure’s data types, we were not satisfied with available JSON types and decided to give EDN a try - that way we would have way more supported types:

Compare the nightmare that is pickling with how simple it is to serialize pure data with edn in clojure. What ends up happening is people passing around JSONs or whatever and writing parsing/encoding code at each end, which makes things unnecessarily more complex, and dangerous, and error prone, and boring, etc...