Array enumeration in RAML

It’s sometimes useful to define enumerated types such as:

type: string
enum: [foo, bar]

to restrict possible values that that type allows.

How about arrays?

With arrays, one may be tempted to write the enumerated list at the same level:

type: array
enum: [one, two, three]

but that is wrong since the enum property refers to the parent type itself, not its children.

This would work though:

type: array
enum: [[one, two], [one, two, three]]

but it would be a tedious task to list all possible combinations, especially for large lists.

However, in RAML, arrays have an items property in which the type of all array items is defined and that's where the enum property of our example above should go:

type: array
items:
  enum: [one, two, three]

Similarly, the equivalent JSON Schema would be:

{
    "type": "array",
    "items": {
        "type": "string",
        "enum": ["one", "two", "three"]
    }
}