# File lib/trollop.rb, line 800
  def parse(paramlist, _neg_given)
    paramlist.map do |pg|
      pg.map do |param|
        if param =~ /^(stdin|-)$/i
          $stdin
        else
          require 'open-uri'
          begin
            open param
          rescue SystemCallError => e
            raise CommandlineError, "file or url for option '#{self.name}' cannot be opened: #{e.message}"
          end
        end
      end
    end
  end