parameterized schema

[Benjmhart]

it would be useful to have higher order types defined which can be supplied with a parameter, such as:

$schema wrapper<a>
    $type
        $object
    $property-name "tag"
    $property-schema $string
    $property-name "contents"
    $property-schema a

and this could then be applied in the following manner or similar:

$schema $start
   $type
         wrapper otherSchema

or

    $property-schema wrapper otherSchema

This is particularly relevant when dealing with protocols where a default wrapper shape is mandatory across many request/response types. in my case, JsonWSP.

especially combined with the modular schema feature request this would allow us to express the