YAML version compatibility¶

ryl targets YAML 1.2¶

ryl is built on the saphyr parser, which implements YAML 1.2 strictly. yamllint, by comparison, is built on PyYAML, which defaults to YAML 1.1 semantics for boolean and other implicit type resolution.

Most YAML files do not exercise the parts of the language where the two versions disagree, so in practice the difference rarely shows up. The two places it matters in ryl are:

• The quoted-strings rule when used with required: "only-when-needed".
• Parsing of .yamllint / .yamllint.yaml / .yamllint.yml configuration files inherited from yamllint.

What is different in YAML 1.2¶

ryl applies YAML 1.2 semantics to both linted files and configuration files.

Implications for the quoted-strings rule¶

With quote-type: double, required: only-when-needed, yamllint considers "yes" to need quoting (because the bareword would parse as a boolean in 1.1), so it accepts the quoted form. ryl considers "yes" to be redundantly quoted (because the bareword would parse as a string in 1.2) and reports it.

If your project still wants quotes around YAML 1.1 truthy words to protect consumers that use 1.1 parsers, set:

[rules.quoted-strings]
required = true              # always quote, regardless of type
quote-type = "double"

…or rely on the truthy rule to flag bareword booleans instead and keep quoted-strings off.

Implications for configuration files¶

ryl parses .yamllint / .yamllint.yaml / .yamllint.yml configs with the same strict YAML 1.2 parser. A yamllint configuration that uses 1.1 booleans like:

rules:
  truthy:
    check-keys: no       # 1.1 boolean false
  empty-values:
    forbid-in-block-mappings: yes

…will fail to parse in ryl. Replace these values with their YAML 1.2 equivalents (false / true) or run the built-in converter to produce a .ryl.toml instead:

ryl --migrate-configs --migrate-write

The migration converter writes TOML, where booleans have an unambiguous syntax independent of YAML version.

Implications for documents being linted¶

The rules below behave the way they do because ryl reads inputs as YAML 1.2. Most of these are intentional and align with yamllint when yamllint is configured for 1.2 explicitly:

• truthy — the rule itself still recognises the 1.1 truthy word list as ambiguous and flags barewords like yes or On so authors are warned about consumers that still use 1.1.
• octal-values — 0755 is treated as decimal 755; the rule can still report it for ambiguity reasons.
• float-values — numeric formats follow the 1.2 spec.

For documents that need to be portable between 1.1 and 1.2 consumers, the safest pattern is to quote any bareword that 1.1 would coerce. ryl will not get in your way as long as quoted-strings.required is true (or unset / disabled) rather than "only-when-needed".