filtering files in rake-pipeline

Assetfile.rb

match "**/*.js" do
  # block so uglify doesn't change name
  uglify do |input|
    input
  end
  # immediate has to come before modernizr
  # block to filter if files even end up in a file at all
  # need to decide between immediate and main (top of bottom of html file)
  concat ['immediate.js', 'modernizr-2.0.min.js'], do |filename|
    immedateGroup = ['immediate.js', 'modernizr-2.0.min.js']
    laterGroup = ['main.js', 'jquery.form.js', 'jquery.animate-enhanced.min.js']
    if immedateGroup.include?(filename.split('/').last)
      "immediate.min." + VERS + ".js"
    elsif laterGroup.include?(filename.split('/').last)
      "main.min." + VERS + ".js"
    end
  end
end