Add AttributeCodable support for Decimal

Author: colemancda

Sources/CoreModel/Decodable.swift

@@ -161,6 +161,16 @@ extension Data: AttributeDecodable {
     }
 }
 
+extension Decimal: AttributeDecodable {
+    
+    public init?(attributeValue: AttributeValue) {
+        guard case let .decimal(value) = attributeValue else {
+            return nil
+        }
+        self = value
+    }
+}
+
 extension Float: AttributeDecodable {
 
     public init?(attributeValue: AttributeValue) {

Sources/CoreModel/Decoder.swift

@@ -192,14 +192,6 @@ internal extension ModelDataDecoder {
                 throw DecodingError.dataCorrupted(DecodingError.Context(codingPath: codingPath, debugDescription: "Cannot decode \(type) from identifier \(id)"))
             }
             return value as! T
-        } else if type == Data.self {
-            return try decodeAttribute(Data.self, forKey: key) as! T
-        } else if type == Date.self {
-            return try decodeAttribute(Date.self, forKey: key) as! T
-        } else if type == UUID.self {
-            return try decodeAttribute(UUID.self, forKey: key) as! T
-        } else if type == URL.self {
-            return try decodeAttribute(URL.self, forKey: key) as! T
         } else if let decodableType = type as? AttributeDecodable.Type {
             return try decodeAttribute(decodableType, forKey: key) as! T
         } else {

Sources/CoreModel/Encodable.swift

@@ -147,3 +147,8 @@ extension URL: AttributeEncodable {
 
     public var attributeValue: AttributeValue { .url(self) }
 }
+
+extension Decimal: AttributeEncodable {
+    
+    public var attributeValue: AttributeValue { .decimal(self) }
+}

Sources/CoreModel/Encoder.swift

@@ -123,15 +123,7 @@ internal extension ModelDataEncoder {
 
     func setEncodable <T: Encodable> (_ value: T, forKey key: PropertyKey) throws {
 
-        if let data = value as? Data {
-            try setAttribute(data.attributeValue, forKey: key)
-        } else if let date = value as? Date {
-            try setAttribute(date.attributeValue, forKey: key)
-        } else if let uuid = value as? UUID {
-            try setAttribute(uuid.attributeValue, forKey: key)
-        } else if let url = value as? URL {
-            try setAttribute(url.attributeValue, forKey: key)
-        } else if let encodable = value as? AttributeEncodable {
+        if let encodable = value as? AttributeEncodable {
             try setAttribute(encodable.attributeValue, forKey: key)
         } else {
             // encode using Encodable, container should write directly.