Adds the seeAlso aside (swiftlang#96)

“See Also” is a common kind of aside that folks parsing markdown may wish to consider. For Swift-DocC specifically, there is a lot of pre-DocC Swift documentation content that uses this style of callout: ``` - SeeAlso: ``` In order to gracefully transition this content over to Swift-DocC style asides, we should add support for them.

Author: ethan-kusters

Sources/Markdown/Interpretive Nodes/Aside.swift

@@ -1,7 +1,7 @@
 /*
  This source file is part of the Swift.org open source project
 
- Copyright (c) 2021-2022 Apple Inc. and the Swift project authors
+ Copyright (c) 2021-2023 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
@@ -92,6 +92,9 @@ public struct Aside {
  /// A "throws" aside.
  public static let `throws` = Kind(rawValue: "Throws")!
 
+ /// A "seeAlso" aside.
+ public static let seeAlso = Kind(rawValue: "SeeAlso")!
+ 
  /// A collection of preconfigured aside kinds.
  public static var allCases: [Aside.Kind] {
  [
@@ -118,9 +121,35 @@ public struct Aside {
  todo,
  version,
  `throws`,
+ seeAlso,
  ]
  }
 
+ /// The heading text to use when rendering this kind of aside.
+ ///
+ /// For multi-word asides this value may differ from the aside's ``rawValue``.
+ /// For example, the ``seeAlso`` aside's `rawValue` is `"SeeAlso"` but its
+ /// `displayName` is `"See Also"`.
+ /// Likewise, ``nonMutatingVariant``'s `rawValue` is
+ /// `"NonMutatingVariant"` and its `displayName` is `"Non-Mutating Variant"`.
+ ///
+ /// For simpler, single-word asides like ``bug``, the `displayName` and `rawValue` will
+ /// be the same.
+ public var displayName: String {
+ switch self {
+ case .seeAlso:
+ return "See Also"
+ case .nonMutatingVariant:
+ return "Non-Mutating Variant"
+ case .mutatingVariant:
+ return "Mutating Variant"
+ case .todo:
+ return "To Do"
+ default:
+ return rawValue
+ }
+ }
+ 
  /// The underlying raw string value.
  public var rawValue: String