I recommend taking a look at TOML [1] as an alternative to YAML for many situations.

  Objectives: 

  TOML aims to be a minimal configuration file format 
  that's easy to read due to obvious semantics. TOML is
  designed to map unambiguously to a hash table. TOML
  should be easy to parse into data structures in a wide
  variety of languages.

A reddit thread titled "YAML vs TOML" has some merit [2].

  YAML downsides:
  - Implicit typing causes surprise type changes. (e.g. 
    put 3 where you previously had a string and it will
    magically turn into an int).
  - A bunch of nasty "hidden features" like node anchors
    and references that make it look unclear (although to
    be fair a lot of people don't use this).

  TOML downsides:
  - Noisier syntax (especially with multiline strings).
  - The way arrays/tables are done is confusing, especially 
    arrays of tables.

Rust uses TOML to configure its build system, Cargo [3].

[1]: https://github.com/toml-lang/toml

[2]: https://www.reddit.com/r/devops/comments/6f82nu/yaml_vs_toml...

[3]: https://doc.rust-lang.org/cargo/getting-started/first-steps....