require_or_load

# File activesupport/lib/active_support/dependencies.rb, line 320
    def require_or_load(file_name, const_path = nil)
      log_call file_name, const_path
      file_name = $1 if file_name =~ /^(.*)\.rb$/
      expanded = File.expand_path(file_name)
      return if loaded.include?(expanded)

      # Record that we've seen this file *before* loading it to avoid an
      # infinite loop with mutual dependencies.
      loaded << expanded

      begin
        if load?
          log "loading #{file_name}"

          # Enable warnings iff this file has not been loaded before and
          # warnings_on_first_load is set.
          load_args = ["#{file_name}.rb"]
          load_args << const_path unless const_path.nil?

          if !warnings_on_first_load or history.include?(expanded)
            result = load_file(*load_args)
          else
            enable_warnings { result = load_file(*load_args) }
          end
        else
          log "requiring #{file_name}"
          result = require file_name
        end
      rescue Exception
        loaded.delete expanded
        raise
      end

      # Record history *after* loading so first load gets warnings.
      history << expanded
      return result
    end