Projectionist

Occasionally one sees:

  def foo(options = {})
    [options[:bar]].flatten.map do |arg|


	
…

    end

  end

If options[:bar] is a single value you want it to be treated like a collection. If it’s a collection then you want to flatten it so the surrounding [] doesn’t create a collection within a collection.

Spat rather than flatten:

  def foo(options = {})
    [*options[:bar]].map do |arg|


	
…

    end

  end

The example assumes that the option is always set (either by a default or otherwise).

(Thank you to Ryan Davis for making me realize that there was something wrong with my initial post)