func implementation()

in Sources/SourceKitLSP/SourceKitServer.swift [1048:1093]
41 lines of code
4 McCabe index (conditional complexity)

  func implementation(
    _ req: Request<ImplementationRequest>,
    workspace: Workspace,
    languageService: ToolchainLanguageServer
  ) {
    let symbolInfo = SymbolInfoRequest(textDocument: req.params.textDocument, position: req.params.position)
    let index = self.workspace?.index
    let callback = callbackOnQueue(self.queue) { (result: Result<SymbolInfoRequest.Response, ResponseError>) in
      guard let symbols: [SymbolDetails] = result.success ?? nil, let symbol = symbols.first else {
        if let error = result.failure {
          req.reply(.failure(error))
        } else {
          req.reply(.locations([]))
        }
        return
      }

      guard let usr = symbol.usr, let index = index else {
        return req.reply(.locations([]))
      }

      var occurs = index.occurrences(ofUSR: usr, roles: .baseOf)
      if occurs.isEmpty {
        occurs = index.occurrences(relatedToUSR: usr, roles: .overrideOf)
      }

      let locations = occurs.compactMap { occur -> Location? in
        if occur.location.path.isEmpty {
          return nil
        }
        return Location(
          uri: DocumentURI(URL(fileURLWithPath: occur.location.path)),
          range: Range(Position(
            line: occur.location.line - 1, // 1-based -> 0-based
            // FIXME: we need to convert the utf8/utf16 column, which may require reading the file!
            utf16index: occur.location.utf8Column - 1
            ))
        )
      }

      req.reply(.locations(locations))
    }
    let request = Request(symbolInfo, id: req.id, clientID: ObjectIdentifier(self),
                          cancellation: req.cancellationToken, reply: callback)
    languageService.symbolInfo(request)
  }