[klibertp]

There's a JSON parser in the standard library (http://nim-lang.org/docs/json.html). It works by declaring discriminated union (called enum in Nim) of possible JSON types, declared here: https://github.com/nim-lang/Nim/blob/master/lib/pure/json.ni... You get a tree of nodes out of the parser and switch (lightweight pattern matching) on each node type. Nim does exhaustiveness checking, so you will never fail to handle some kind of JSON node by accident. You're forced to deal with nulls explicitly, either via pattern matching or convenience functions like `getOrDefault`.

It's not as nice as F# Type Providers, but it's workable. You could write something similar to Type Providers with macros (given a schema or sample), but I don't know if someone tried this already. With all the standard operators (like property access/assignment and toString equivalent) overloaded to support JSON, it feels quite natural. I wrote a little script consuming a JSON service, it looks like this for example: https://gist.github.com/piotrklibert/b2ba0774244bb7368748a3b...

Nim has its peculiarities and rough edges (it's not even at 1.0 yet), but it's expressive (many of the construct typically built-in in languages are implemented as libraries) and fast. C-level fast, without a huge runtime, so for things like this script it's 4x-16x (IIRC, when reading cached data from disk) faster than compiled F# version (on Mono), for example. My impression of the language is that it's pragmatic and flexible. Also opinionated, which may be both a good and a bad thing, depending on what are your preferences.

[m_mueller]

> var res = get_url().getContent().parseJson()

> res = res["rates"]["PLN"]

That does look quite reasonable yes. You're right, for a statically typed language it does feels quite dynamic. I think a good blog article comparing Nim to Swift would be very interesting, I couldn't find such a thing.

Thanks for your input!

Edit: Looking at http://roadfiresoftware.com/2015/10/how-to-parse-json-with-s... I think I'd much rather have Nim. This is exactly the sort of thing where types get in the way and slow development down tremendously. If I get external data it should be enough to just be aware that all accesses return an "optional", which has to be dealt with accordingly as part of error handling. Letting types get in the way as well is basically doing the work twice.