YAML document from hell (2023)

not only is YAML a pain but JSON has native parser in major languages, while not yaml. I find it crazy some people are still actively choosing this over JSON (or alternatives)

So... what are the good alternatives to yaml?

For quite some time I thought toml, but the way you can spread e.g. lists all over the document can also cause some headaches.

Dhall is exactly my kind of type fest but you can hit a hard brick wall because the type system is not as strong as you think.

I wish I had a good answer for you. I've been dissatisfied with Dhall, Nickle, Cue, and possibly others. Dhall's type system is both too strong (you have to plumb type variables by hand if you want to do any kind of routine FP idioms) and too weak (you can't really _do_ much with record types - it's really hard to swizzle and rearrange deeply nested records).

On top of that, the grammar is quite difficult to parse. You need a parser that can keep several candidate parses running in parallel (like the classic `Parser a = Parser (String -> [(a, String)])` type) to disambiguate some of the gnarlier constructs (maybe around file paths, URLs, and record accesses? I forget). The problem with this is that it makes the parse errors downright inscrutable, because it's hard to know when the parse you actually intended was rejected by the parser when the only error you get was "Unexpected ','".

Oh, and you can't multiply integers together, only naturals.

Maybe Nix in pure eval mode, absurd as that sounds?

I think the best thing for tools to do is to take and return JSON (possible exception: tools whose format is simple enough for old-school UNIX-style stdin/stdout file formats). Someone will come up with a good functional abstraction over JSON eventually, and until then you can make do with Dhall, YAML, or whatever else.

stupid question: why dont they announce a newer version of YAML that is not backwards compatible and allow only quoted strings in their parser?

We found yaml to be a great exchange format for electronic exam data. It allows us to put student submitted answers and source code into a yaml file and there is no weird escaping. It's very readable with a text editor. And then we just add notes and a score as a list below and then there's the next submission.

For readability of large blocks of texts that may or may not contain various special characters and newlines the only other alternative we have seen was XML, but that is very verbose.

So what the author finds as a negative, the many string formats, are exactly what drew us to yaml in the first place.