Flatten file directories (fixes #159)

Sources/MigrationResult.swift

@@ -0,0 +1,136 @@
+//
+//  MigrationResult.swift
+//  CoreStore
+//
+//  Copyright © 2015 John Rommel Estropia
+//
+//  Permission is hereby granted, free of charge, to any person obtaining a copy
+//  of this software and associated documentation files (the "Software"), to deal
+//  in the Software without restriction, including without limitation the rights
+//  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+//  copies of the Software, and to permit persons to whom the Software is
+//  furnished to do so, subject to the following conditions:
+//
+//  The above copyright notice and this permission notice shall be included in all
+//  copies or substantial portions of the Software.
+//
+//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+//  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+//  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+//  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+//  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+//  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+//  SOFTWARE.
+//
+
+import Foundation
+
+
+// MARK: - MigrationResult
+
+/**
+ The `MigrationResult` indicates the result of a migration.
+ The `MigrationResult` can be treated as a boolean:
+ ```
+ CoreStore.upgradeSQLiteStoreIfNeeded { transaction in
+     // ...
+     let result = transaction.commit()
+     if result {
+         // succeeded
+     }
+     else {
+         // failed
+     }
+ }
+ ```
+ or as an `enum`, where the resulting associated object can also be inspected:
+ ```
+ CoreStore.beginAsynchronous { transaction in
+     // ...
+     let result = transaction.commit()
+     switch result {
+     case .success(let hasChanges):
+         // hasChanges indicates if there were changes or not
+     case .failure(let error):
+         // error is a CoreStoreError enum value
+     }
+ }
+ ```
+ */
+public enum MigrationResult: Hashable {
+    
+    /**
+     `MigrationResult.success` indicates either the migration succeeded, or there were no migrations needed. The associated value is an array of `MigrationType`s reflecting the migration steps completed.
+     */
+    case success([MigrationType])
+    
+    /**
+     `SaveResult.failure` indicates that the migration failed. The associated object for this value is the a `CoreStoreError` enum value.
+     */
+    case failure(CoreStoreError)
+    
+    
+    /**
+     Returns `true` if the result indicates `.success`, `false` if the result is `.failure`.
+     */
+    public var isSuccess: Bool {
+        
+        switch self {
+            
+        case .success: return true
+        case .failure: return false
+        }
+    }
+    
+    
+    // MARK: Equatable
+    
+    public static func == (lhs: MigrationResult, rhs: MigrationResult) -> Bool {
+        
+        switch (lhs, rhs) {
+            
+        case (.success(let migrationTypes1), .success(let migrationTypes2)):
+            return migrationTypes1 == migrationTypes2
+            
+        case (.failure(let error1), .failure(let error2)):
+            return error1 == error2
+            
+        default:
+            return false
+        }
+    }
+    
+    
+    // MARK: Hashable
+    
+    public var hashValue: Int {
+        
+        switch self {
+            
+        case .success(let migrationTypes):
+            return true.hashValue
+                ^ migrationTypes.map { $0.hashValue }.reduce(0, ^).hashValue
+            
+        case .failure(let error):
+            return false.hashValue ^ error.hashValue
+        }
+    }
+    
+    
+    // MARK: Internal
+    
+    internal init(_ migrationTypes: [MigrationType]) {
+        
+        self = .success(migrationTypes)
+    }
+    
+    internal init(_ error: CoreStoreError) {
+        
+        self = .failure(error)
+    }
+    
+    internal init(_ error: Error) {
+        
+        self = .failure(CoreStoreError(error))
+    }
+}