Rule suggestion: List style (brackets)

[carlpett]

I'd like to propose a rule for checking style for lists. We have some files where we mix the two forms:

foo: ["a","b","c"]
bar:
  - 1
  - 2
  - 3

Having options to only allow either, or consistent would be great!

(To some extent also dicts, where we sometimes get baz: { qux: true }, but this seems less common)

[adrienverge]

Hey, this is a good idea.

• This could be done by adding some options to braces and brackets, for example:

  brackets:
    forbid: true

  Drawback: we cannot force the flow style (the one with brackets) and forbid the block style (the multi-line one).

• Another option would be to add 2 other rules:

  mappings-style:
    type: block | flow | whatever
  sequences-style:
    type: block | flow | whatever

[make-github-pseudonymous-again]

How difficult would it be to implement this?