pyyaml VS groq-test-suite

PyYAML knew about the breakage since january 2022[0], and nothing really happened. After a year and a half with lots of alphas and betas, I don't think there is much cython could do, short of fixing PyYAML themselves.

[0]: https://github.com/yaml/pyyaml/issues/601

They did finally change the default, in PyYAML 6, after many many bugs pointing out that their previous approach is broken (including one by yours truly), so the default is now safe.

Note some parsers, most notably pyyaml are still at yaml 1.1, because 13 years is just not enough time to update it.

That part of the YAML 1.2 spec is in conflict with reality, though. The base of YAML 1.1 documents is large enough that a backwards-incompatible change to default behavior is for practical purposes impossible.

YAML 1.1 was released in 2005, and 1.2 in 2009 -- only four years later. But here we are, in 2022, and YAML 1.1 is still the default (in many cases, only) version supported. That's why the "Norway problem" persists -- it's not possible for the parser to know whether an un-versioned YAML document containing "a: no" should parse the same as {"a": false} or {"a": "no"}.

Python (PyYAML) doesn't support 1.2 yet: https://github.com/yaml/pyyaml/issues/116

Ruby (Psych) ditto -- I can't even find a tracking issue to enable it.

Go (go-yaml) is a mixture of YAML 1.1 and 1.2, depending on the author's preferences.

Also, as a rough guideline, you can't have a backwards-incompatible revision of a versioned spec declare that it's the new default version, because that breaks all existing users.

Many parsers either default to YAML pre-1.2 or do not even expose a YAML 1.2 option. PyYAML has no 1.2 option, for example. So unless Ansible is using something other than PyYAML...

Relevant (open) PR: https://github.com/yaml/pyyaml/pull/555

Are you perhaps talking about decimal.Decimal? https://github.com/yaml/pyyaml/issues/255

TOML also has a few restrictions, such as not supporting mixed-type arrays like [1, "hello", true], or arrays at the root of the data. JSON can represent any TOML value (as far as I know), but TOML cannot represent any JSON value.

At my company we use YAML a lot for table-driven tests (e.g. [1]), and this not only means lots of nested arrays, but also having to represent pure data (i.e. the expected output of a test), which requires a format that supports encoding arbitrary data structures.

[1] https://github.com/sanity-io/groq-test-suite/