An Autocodable template, similar to the one @khanlou wrote about

AutoCodable.stencil

{% for type in types.implementing.AutoCodable %}

public extension {{type.name}} {
    var encodable{{type.name}}: Encodable{{ type.name }} {
        return Encodable{{ type.name }}(object: self)
    }
}

open class Encodable{{ type.name }}: NSObject, NSCoding {
    public let object: {{ type.name }}!
    
    public init(object: {{ type.name }}?) {
        self.object = object
    }
    
    required public init?(coder decoder: NSCoder) {
        self.object = {{ type.name }}()
        {% for variable in type.allVariables %}
        {% if variable.typeName.name|hasPrefix:"DeviceType" %}
        self.object?.{{ variable.name }} = DeviceType(rawValue: decoder.decodeObject(forKey: "{{ variable.name }}") as! String)
        {% elif variable.typeName.name|hasPrefix:"[String]?" or variable.typeName.name|hasPrefix:"[String:String]?" %}
        self.object?.{{ variable.name }} = decoder.decodeObject(forKey: "{{ variable.name }}") as? {{ variable.unwrappedTypeName }}
        {% elif variable.typeName.name|hasPrefix:"[" %}
        guard let encodable_{{ variable.name }} = decoder.decodeObject(forKey: "{{ variable.name }}") as? [Encodable{{ variable.typeName.name|replace:"[",""|replace:"]","" }}] else { return nil }
        self.object?.{{ variable.name }} = encodable_{{ variable.name }}.flatMap({ $0.{{ variable.typeName.name|replace:"[",""|replace:"]",""| lowerFirstWord}} })
        {% elif variable.isOptional and variable.type.implements.AutoCodable %}
        let encodable_{{ variable.name }} = decoder.decodeObject(forKey: "{{ variable.name }}") as? Encodable{{ variable.unwrappedTypeName }}
        self.object?.{{ variable.name }} = encodable_{{variable.name}}?.object
        {% elif variable.isOptional and not variable.type.implements.AutoCodable %}
        self.object?.{{ variable.name }} = decoder.decodeObject(forKey: "{{ variable.name }}") as? {{ variable.unwrappedTypeName }}
        {% elif variable.type.implements.AutoCodable %}
        guard let encodable_{{ variable.name }} = decoder.decodeObject(forKey: "{{ variable.name }}") as? Encodable{{ variable.typeName }},
        self.object?.{{ variable.name }} = encodable_{{ variable.name }}.object else { return nil }
        {% else %}
        guard let {{ variable.name }} = decoder!!.decodeObject(forKey: "{{ variable.name }}") as? {{ variable.typeName }} else { return nil }
        {% endif %}
        {% endfor %}
    }      
            
    public func encode(with encoder: NSCoder) {
        {% for variable in type.allVariables %}
        {% if variable.typeName.name|hasPrefix:"DeviceType" %}
        encoder.encode(object?.{{ variable.name }}?.rawValue, forKey: "{{ variable.name }}")
        {% elif variable.typeName.name|hasPrefix:"[String]?" or variable.typeName.name|hasPrefix:"[String:String]?"%}
        encoder.encode(object?.{{ variable.name }}, forKey: "{{ variable.name }}")
        {% elif variable.typeName.name|hasPrefix:"[" %}
        let encoded_{{ variable.name }} = object?.{{ variable.name }}.map({ return Encodable{{ variable.typeName.name|replace:"[",""|replace:"]","" }}({{ variable.typeName.name|replace:"[",""|replace:"]",""| lowerFirstWord }}: $0) })
        encoder.encode(encoded_{{ variable.name }}, forKey: "{{ variable.name }}")
        {% elif variable.type.implements.AutoCodable %}
        encoder.encode(Encodable{{ variable.unwrappedTypeName }}(object: object?.{{ variable.name }}), forKey: "{{ variable.name }}")
        {% else %}
        encoder.encode(object?.{{ variable.name }}, forKey: "{{ variable.name }}")
        {% endif %}
        {% endfor %}
    }
}

{% endfor %}