Add support for struct mirroring (#10)

Sources/Beet/Beets/Enums.swift

@@ -245,6 +245,16 @@ public func mirrored(value: Any) -> (label: String, params: [String: Any]) {
         return ("\(value)", dictionary)
     }
 
+    if reflection.displayStyle == .struct {
+        var dictionary = [String: Any]()
+        for child in reflection.children {
+            if let label = child.label {
+                dictionary[label] = child.value
+            }
+        }
+        return ("\(value)", dictionary)
+    }
+
     if reflection.displayStyle == .enum, let associated = reflection.children.first {
         let values = Mirror(reflecting: associated.value).children
         var valuesArray = [String: Any]()

Sources/Beet/Struct.Fixable.swift

@@ -78,18 +78,21 @@ public class FixableBeetStruct<Class>: FixableBeet {
     }
 
     public func toFixedFromValue(val: Any) -> FixedSizeBeet {
-        let value = val as! Args
-        let argsKeys = value.keys
-        var fixedFields: [FixedBeetField] = []
+        let mirror = mirrored(value: val)
 
-        for i in 0..<self.fields.count {
-            let (key, beet) = self.fields[i]
-            assert(argsKeys.contains {
-                $0 == key
-            }, "Value with keys [ \(argsKeys) ] should include struct key '\(key)' but doesn't.")
-            let argValue = value[key]
-            let fixedBeet = fixBeetFromValue(beet: beet, val: argValue)
-            fixedFields.append((key, fixedBeet))
+        var dictionary: [AnyHashable: Any] = [:]
+        for param in mirror.params {
+            dictionary[param.key] = param.value
+        }
+
+        var fixedFields: [FixedBeetField] = []
+        for f in fields {
+            switch f.beet {
+            case .fixedBeet(let type):
+                fixedFields.append((f.type, type))
+            case .fixableBeat(let type):
+                fixedFields.append((f.type, type.toFixedFromValue(val: dictionary[f.type]!)))
+            }
         }
 
         if self.description != FixableBeetStruct_TYPE {