YAML::AppConfig extends the work done in Config::YAML and
YAML::ConfigFile to allow more flexiable configuration files.

Your configuration is stored in YAML and then parsed and presented to
you via YAML::AppConfig. Settings can be referenced using get and set
methods and settings can refer to one another by using variables of
the form $foo, much in the style of AppConfig.

WWW: https://metacpan.org/release/YAML-AppConfig