class IRB::Context

def history_file
  IRB.conf[:HISTORY_FILE]
end

def history_file=(hist)
  IRB.conf[:HISTORY_FILE] = hist
end

def init_save_history
  unless (class<<@io;self;end).include?(HistorySavingAbility)
    @io.extend(HistorySavingAbility)
  end
end

def save_history
  IRB.conf[:SAVE_HISTORY]
end

def save_history=(val)
  IRB.conf[:SAVE_HISTORY] = val
  if val
    main_context = IRB.conf[:MAIN_CONTEXT]
    main_context = self unless main_context
    main_context.init_save_history
  end
end