class Rack::Reloader

def safe_load(file, mtime, stderr = $stderr)

A safe Kernel::load, issuing the hooks depending on the results 
def safe_load(file, mtime, stderr = $stderr)
  load(file)
  stderr.puts "#{self.class}: reloaded `#{file}'"
  file
rescue LoadError, SyntaxError => ex
  stderr.puts ex
ensure
  @mtimes[file] = mtime
end