| //===---------------- SourcePresence.swift - Source Presence --------------===// |
| // |
| // This source file is part of the Swift.org open source project |
| // |
| // Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors |
| // Licensed under Apache License v2.0 with Runtime Library Exception |
| // |
| // See https://swift.org/LICENSE.txt for license information |
| // See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors |
| // |
| //===----------------------------------------------------------------------===// |
| |
| import Foundation |
| |
| /// An indicator of whether a Syntax node was found or written in the source. |
| /// |
| /// A `missing` node does not mean, necessarily, that the source item is |
| /// considered "implicit", but rather that it was not found in the source. |
| public enum SourcePresence: String, Codable { |
| /// The syntax was authored by a human and found, or was generated. |
| case present = "Present" |
| |
| /// The syntax was expected or optional, but not found in the source. |
| case missing = "Missing" |
| } |
| |
| extension SourcePresence: ByteTreeScalarDecodable { |
| static func read(from pointer: UnsafeRawPointer, size: Int) -> SourcePresence { |
| let rawValue = pointer.bindMemory(to: UInt8.self, capacity: 1).pointee |
| switch rawValue { |
| case 0: return .missing |
| case 1: return .present |
| default: |
| fatalError("Unknown source presence \(rawValue)") |
| } |
| } |
| } |
