yaml-language-server VS pyyaml

Does anyone know how to get yaml formatting working with yamlls (https://github.com/redhat-developer/yaml-language-server)?

I'm starting to work with kubernetes and it would be really nice to have the full completion that Redhat's language server offers for k8s yaml files if you associate the right schema with it.

Most modern editors and IDEs support the Language Server Protocol, which powers the code completion, validation, and tooltip features. Combined with a Yaml Language Server, we can get rich completion for Yaml files!

I don't think the YAML language server can handle this. Here's the issue about this: https://github.com/redhat-developer/yaml-language-server/issues/220

Here's an example .dir-locals.el configuration I'm using with yaml-language-server

Check out https://github.com/redhat-developer/yaml-language-server if you want to get that IDE experience with YAML from those openapi specs

For our custom LSP, we'll start by forking the yaml-language-server maintained by redhat.

One of the things I was missing in my nvim setup was the ability to choose the schema that yamlls uses in the various buffers. This server also intentionally leaves out some cool features like content aware schema detection and, since I could never get the Schema Store functionality to work when paired with the hard-coded Kubernetes support in the language server… I have converted all the hacky lua I had into this plugin. Sharing it here in case it is useful to anyone https://github.com/someone-stole-my-name/yaml-companion.nvim

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