Update InlayHint to follow the current proposal

See microsoft/language-server-protocol#1249

Author: fwcd

Sources/LanguageServerProtocol/SupportTypes/InlayHint.swift

@@ -12,44 +12,37 @@
 
 /// Represents an inline annotation displayed by the editor in a source file.
 public struct InlayHint: ResponseType, Codable, Hashable {
-  /// The range of the token to be annotated.
-  @CustomCodable<PositionRange>
-  public var range: Range<Position>
-
-  /// The side of the token on which to place the hint.
-  public var side: InlayHintSide
+  /// The position within the code that this hint is attached to.
+  public var position: Position
 
   /// The hint's kind, used for more flexible client-side styling.
-  public let kind: InlayHintKind
+  public let category: InlayHintCategory?
 
   /// The hint's text, e.g. a printed type
   public let label: String
 
   public init(
-    range: Range<Position>,
-    side: InlayHintSide = .after,
-    kind: InlayHintKind,
+    position: Position,
+    category: InlayHintCategory? = nil,
     label: String
   ) {
-    self.range = range
-    self.side = side
-    self.kind = kind
+    self.position = position
+    self.category = category
     self.label = label
   }
 }
 
-/// The side of a token on which to place an inlay hint.
-public enum InlayHintSide: Int, Codable, Hashable {
-  case before = 0
-  case after = 1
-}
-
 /// A hint's kind, used for more flexible client-side styling.
-public enum InlayHintKind: Int, Codable, Hashable {
-  /// let x: Hint
-  case bindingType = 0
-  /// { (x: Hint) in
-  case parameterType = 1
-  /// .method(): Hint
-  case methodChainType = 2
+public struct InlayHintCategory: RawRepresentable, Codable, Hashable {
+  public var rawValue: String
+
+  public init(rawValue: String) {
+    self.rawValue = rawValue
+  }
+
+  /// A parameter label. Note that this case is not used by
+  /// Swift, since Swift already has explicit parameter labels.
+  public static let parameter: InlayHintCategory = InlayHintCategory(rawValue: "parameter")
+  /// An inferred type.
+  public static let type: InlayHintCategory = InlayHintCategory(rawValue: "type")
 }

Sources/SourceKitLSP/Swift/SwiftLanguageServer.swift

@@ -1044,9 +1044,8 @@ extension SwiftLanguageServer {
       case .success(let infos):
         let hints = infos.map { info in
           InlayHint(
-            range: info.range,
-            side: .after,
-            kind: .bindingType, // TODO: perform actual classification here
+            position: info.range.upperBound,
+            category: .type,
             label: info.printedType
           )
         }