Re: Should yaml-ts-mode inherit from prog-mode?

[Yuri Khan]

On Tue, 21 Mar 2023 at 21:14, Rudolf Schlatte <rudi@constantly.at> wrote:

> One meaningful behavior for `fill-paragraph' could be to allow it only
> within YAML flowed blocks and flow scalars (see
> https://yaml-multiline.info):
>
>     script: |
>       # this block cannot be refilled.
>       apt-get -y update
>       apt-get -y install my-necessary-package

This is reasonable behavior for literal-styled YAML blocks containing
a sequence of shell commands, or formatted code in a programming
language, or other line-break-sensitive content such as an embedded
YAML document. Swiping an example from [1]:

    env1:
      nova:
        flavor: "30"
        nics:
          - net_id: db6e78cb-99fa-4223-9a6f-3b4a9b486d9b
        userdata: |
          #cloud-config
          disable_root: False
          ssh_pwauth: True
          chpasswd:
            list: |
              root: password

[1]: https://medium.com/@george.shuklin/embedding-yaml-into-yaml-3511246d7ea7

On the other hand, for example, OpenAPI specifications accept Markdown
in several of its properties. My personal preference for these is to
notate them as literal-styled blocks so that joining lines into a
single paragraph happens in the Markdown processor.

In these cases, some users might want to ‘fill-paragraph’ Markdown
paragraphs inside a literal-styled YAML block.

    description: |
      Create a new foo
      and return a 201 with `Location:` header set.

      If the input data is invalid,
      return a 400 with a detailed error report.

Without knowing the syntax for the YAML string value, there is not
enough information to allow or restrict ‘fill-paragraph’.

A sensible compromise could be to allow ‘fill-paragraph’ at user’s
discretion in all string literals, but recognize YAML’s string start
and end as paragraph boundaries.