%a{annotate:rdoc:skip}
class Logger
  # <!-- rdoc-file=lib/logger/formatter.rb -->
  # Default formatter for log messages.
  #
  class Formatter
    public

    attr_accessor datetime_format: String?

    # <!--
    #   rdoc-file=lib/logger/formatter.rb
    #   - call(severity, time, progname, msg)
    # -->
    #
    def call: (String severity, Time time, untyped progname, untyped msg) -> String

    private

    # <!--
    #   rdoc-file=lib/logger/formatter.rb
    #   - format_datetime(time)
    # -->
    #
    def format_datetime: (Time time) -> untyped

    # <!--
    #   rdoc-file=lib/logger/formatter.rb
    #   - new()
    # -->
    #
    def initialize: () -> void

    # <!--
    #   rdoc-file=lib/logger/formatter.rb
    #   - msg2str(msg)
    # -->
    #
    def msg2str: (String | Exception | untyped msg) -> String
  end

  interface _Formatter
    def call: (String severity, Time time, untyped progname, untyped msg) -> _ToS
  end
end

Logger::Formatter::Format: String