skylark VS yaml-rust

My stance is that YAML is a good format for configuration management and generation -- it's wonderful at filling gaps as your deployment model increases in complexity to provide a mechanism to "render" your configuration -- much like Skylark [1] does (derived from Google's internal GCL).

YAML ends up being a powerfully declarative model [2] for the state of a data structure, rather than a straight representation, ironically often enough being used in turn for an imperative model like in Ansible [3]. Definitely friendlier than JSON. But personally, I really like YAML because it lets me compose using a traits/mixins-like model using & and , which allows for verbose, structured configuration inputs but concise configuration files.

docker-compose YAML files extension fields [4], imo, are a great example of this type of model in action. When you leave this much pre-deserialization flexibility in your configuration representation, it makes building cool stuff like docker-compose ECS support x-aws- extension keys [5] and other plugin system-type capabilities much more straightforward than, for example, adding a new language feature to HCL.

[1]: https://github.com/google/skylark

Either https://github.com/chyh1990/yaml-rust or https://github.com/dtolnay/serde-yaml for parsing the YAML config file that markdownlint uses

Here's the Rust code so far -- the commented portions are my intent via pseudocode. This is part of an implementation where there's a _yaml_hash member that points to yaml_rust's underlying LinkedHashMap. (Also using anyhow's bail! and Result.)

The first thing I did was to find the crate yaml-rust and it seems it isn't really maintained anymore. It has not been updated in a year and there's a lot of PR's and unresolved issues, the CI is broken... So here is my open ended question.

Currently, my main concern with YAML is that, by the spec, comments are not attached to a particular node (see https://yaml.org/spec/1.2/spec.html#id2767100). As a result, a lot of YAML parsers (like https://github.com/yaml/libyaml and https://github.com/chyh1990/yaml-rust) only filter out the comments during the parsing phase. This makes it less than ideal for a use-case where the configuration file is expected to be modified by both programs and humans.

TOML makes it more trivial to associate comments with a node. This is mainly because the language is simpler though, as the spec is not explicit about that (https://github.com/chyh1990/yaml-rust).