1 /* 2 * Copyright 2021 Google Inc. All rights reserved. 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #if !os(WASI) 18 import Foundation 19 #else 20 import SwiftOverlayShims 21 #endif 22 23 /// Enum is a protocol that all flatbuffers enums should conform to 24 /// Since it allows us to get the actual `ByteSize` and `Value` from 25 /// a swift enum. 26 public protocol Enum { 27 /// associatedtype that the type of the enum should conform to 28 associatedtype T: Scalar & Verifiable 29 /// Size of the current associatedtype in the enum 30 static var byteSize: Int { get } 31 /// The current value the enum hosts 32 var value: T { get } 33 } 34 35 extension Enum where Self: Verifiable { 36 37 /// Verifies that the current value is which the bounds of the buffer, and if 38 /// the current `Value` is aligned properly 39 /// - Parameters: 40 /// - verifier: Verifier that hosts the buffer 41 /// - position: Current position within the buffer 42 /// - type: The type of the object to be verified 43 /// - Throws: Errors coming from `inBuffer` function 44 public static func verify<T>( 45 _ verifier: inout Verifier, 46 at position: Int, 47 of type: T.Type) throws where T: Verifiable 48 { 49 try verifier.inBuffer(position: position, of: type.self) 50 } 51 52 } 53 54 /// UnionEnum is a Protocol that allows us to create Union type of enums 55 /// and their value initializers. Since an `init` was required by 56 /// the verifier 57 public protocol UnionEnum: Enum { 58 init?(value: T) throws 59 } 60