class IRB::Context

def evaluate(line, line_no) # :nodoc:
  @line_no = line_no
  result = nil
  if IRB.conf[:MEASURE] && IRB.conf[:MEASURE_CALLBACKS].empty?
    IRB.set_measure_callback
  end
  if IRB.conf[:MEASURE] && !IRB.conf[:MEASURE_CALLBACKS].empty?
    last_proc = proc do
      result = @workspace.evaluate(line, irb_path, line_no)
    end
    IRB.conf[:MEASURE_CALLBACKS].inject(last_proc) do |chain, item|
      _name, callback, arg = item
      proc do
        callback.(self, line, line_no, arg) do
          chain.call
        end
      end
    end.call
  else
    result = @workspace.evaluate(line, irb_path, line_no)
  end
  set_last_value(result)
end