Variable Types

Variable types can be defined explicitly.

For this concepts definition, $enabled:boolean denotes that $enabled should be a boolean;

CONCEPTS: service.concepts.json

{
    "$service+": {
        "$flag*": "$enabled:boolean"
    }
}

Concepts shadow contains type of a variable under type key;

CONCEPTS SHADOW

{
    "concept": {
        "name": "service",
        "quantifier": { "min": 1 },
        "concept": {
            "name": "flag",
            "quantifier": { "min": 0 },
            "variable": {
                "name": "enabled",
                "type": "boolean"
            }
        }
    }
}

Below is an invalid schema;

SCHEMA: greeting.service.json

{
    "sayGoodbye": {
        "async": "yes"
    }
}

ERROR: 'greeting.service.json' is not valid, 'yes' is not valid a boolean.

Available Variable Types

• :any allows any type of value to be set to corresponding variable
• :string allows only string values
• :boolean allows only true or false
• :number allows only numbers

By default a variable type is implicitly :any, but it can be defined explicitly;

explicit.concepts.json

{
    "$service+": {
        "extra": "$extra:any"
    }
}

implicit.concepts.json

{
    "$service+": {
        "extra": "$extra"
    }
}

Note that explicit.concepts.json will have type: "any" in its shadow, whereas implicit.concepts.json won't.