class Pry

def repl(target=TOPLEVEL_BINDING)
  target = Pry.binding_for(target)
  target_self = target.eval('self')
  exec_hook :before_session, output, target_self
  # cannot rely on nesting.level as

  # nesting.level changes with new sessions

  nesting_level = nesting.size
  Pry.active_instance = self
  # Make sure special locals exist

  target.eval("_pry_ = Pry.active_instance")
  target.eval("_ = Pry.last_result")
  break_level = catch(:breakout) do
    nesting.push [nesting.size, target_self, self]
    loop do
      rep(target)
    end
  end
  nesting.pop
  exec_hook :after_session, output, target_self
  # keep throwing until we reach the desired nesting level

  if nesting_level != break_level
    throw :breakout, break_level
  end
  target_self
end