Yes, no and YAML version 1.2 support

[Polo2]

Hi 👋 ,

Many thanks for all the work here, I'm very glad to parse some YAML files without thinking to it.

Today I had to investigate about a bit more, since a user made us an unexpected feedback, especially for Norwegian 🇳🇴 people.
Let's take this yaml file about languages:

language:
  type: string
  enum: 
    - en
    - fr
    - no
    - it

After some parsing for OpenAPI documentation, generated description was:

Values are en, fr, false, it

Obviously, Norwegian language was translated as false.
Digging into this, I understood it was YAML normal behavior for version 1.1, and that it will be changed with YAML 1.2

Of course we've suggested a workaround, to adapt YAML file with 'no' instead of no.
But just for asking, do you plan to support this new YAML spec version?

[emiltin]

Curious about this too.

[sandstrom]

We've had this issue too.

I think it would be great if Psych would do one of the following:

1. Drop support for YAML 1.1 altogether
2. Switch default behavior to assume YAML 1.2, and only parse it as YAML 1.1 if an option is passed (opt-out for 1.2-only)
3. Support parsing as only YAML 1.2 via an option (opt-in in for 1.2-only).

Among these, I'd prefer 2, but 3 would probably make more sense (and move to 2 in a future major version).

The boolean yes/no parsing, which I think is the only breaking change between YAML 1.1 and 1.2 is a common source of frustration, and the "feature" is rarely used deliberately.

[perlpunk]

There are much more breaking changes than just yes/no, have a look here for all the schema differences: https://perlpunk.github.io/yaml-test-schema/schemas.html

There are also syntax changes, some of them breaking, but rarely used.
For a (hopefully pretty much) complete list, see https://yaml.org/spec/1.2.2/ext/changes/

[sandstrom]

@perlpunk Good points! Much more than I thought, I've updated my comment. Thanks!

[forthrin]

+1. Any roadmap/ETA on this?

(Personally only concerned with not having to quote 'yes', 'no', 'on' and 'off', though obviously it's either 1.1 or 1.2!)