The `# -*- coding: utf-8 -*-` headers were useful for Python 2, and
aren't needed for Python 3 where UTF-8 is the default.
yamllint support of Python 2 was dropped in early 2021, see commit
a3fc64d "End support for Python 2".
Let's drop these headers.
Although `yes` and `no` are recognized as booleans by the pyyaml parser,
the correct keywords are `true` and `false` (as highlighted by the newly
added `truthy` rule).
This commit replaces the use of `yes`/`no` by `true`/`false` and
advertise it in the docs, but also makes sure this change is
backward-compatible (so that `yes` and `no` still work).
With `allow-non-breakable-inline-mappings` enabled, every long line is
passed through `loader.peek_token()`. Even lines that are not valid
YAML. For this reason, this code must be wrapped in a `try`/`except`
block.
Closes: #21
This commit extracts the inline mappings logic defined in the previous
commit to a separate config option, as suggested by @adrienverge. I'll
squash this into the previous commit if the change is accepted. (I named
the option slightly differently to what was suggested as I think my
proposal reads better without consulting the docs: I'd be happy to
reconsider this.)