lib.rs

struct Rules<'a> {
  order: Option<Order<'a>>,
  must_exist: Option<bool>,
  must_be_unique: Option<bool>
}

struct Order<'a> {
  paths: Option<Vec<Path<'a>>>,
  sort: Option<Sort>
}

struct Path<'a> {
  exact: Option<&'a str>,
  contains: Option<&'a str>,
  default: Option<bool>
}

struct Sort {
  alphabetical: Option<SortOption>,
  path_component_length: Option<SortOption>
}

enum SortOption {
  Enabled,
  Disabled,
  Reversed
}

sort.json

{
  "rules": {
    "order": {
      "paths": [
        {"exact": "/usr/local/bin"},
        {"exact": "/usr/local/sbin"},
        {"contains": ".rvm"},
        {"default": true}
        {"exact": "/bin"},
        {"exact": "/sbin"}
      ],
      "sort": {
        "alphabetical": "yes",
        "path_component_length": "reverse"
      }
    },
    "must_exist": true,
    "must_be_unique": true
  }
}