Expose Entity properties on EntityType protocol.

Sources/JSONAPI/Resource/Entity.swift

@@ -43,6 +43,18 @@ public protocol EntityType: PrimaryResource {
 
 	typealias Attributes = Description.Attributes
 	typealias Relationships = Description.Relationships
+
+	/// The `Entity`'s Id. This can be of type `Unidentified` if
+	/// the entity is being created clientside and the
+	/// server is being asked to create a unique Id. Otherwise,
+	/// this should be of a type conforming to `IdType`.
+	var id: Identifier { get }
+
+	/// The JSON API compliant attributes of this `Entity`.
+	var attributes: Attributes { get }
+
+	/// The JSON API compliant relationships of this `Entity`.
+	var relationships: Relationships { get }
 }
 
 /// An `Entity` is a single model type that can be

Sources/JSONAPI/Resource/Id.swift

@@ -8,7 +8,7 @@
 /// Any type that you would like to be encoded to and
 /// decoded from JSON API ids should conform to this
 /// protocol. Conformance for `String` is given.
-public protocol RawIdType: Codable, Equatable {}
+public protocol RawIdType: Codable, Hashable {}
 
 /// If you would like to be able to create new
 /// Entities with Ids backed by a RawIdType then
@@ -32,7 +32,7 @@ public struct Unidentified<EntityDescription: JSONAPI.EntityDescription>: Identi
 	public var description: String { return "Id(Unidentified)" }
 }
 
-public protocol IdType: Identifier, CustomStringConvertible {
+public protocol IdType: Identifier, Hashable, CustomStringConvertible {
 	associatedtype RawType: RawIdType
 	
 	var rawValue: RawType { get }