a small sample of how to use ERB templates in your file without making your code fugly

in-file_templates.rb

require 'erb'

files = Dir.glob("*")
templates = DATA.read.split("---")
templates.each do |template|
  ERB.new(template, nil, '%-').run
end

__END__
package {
  public class Assets {
<% files.each do |path, var_name| -%>
    [Embed(source="<%= path %>")]
    public static var <%= var_name %>:Class;
<% end -%>
  }
}
---
package {
  public class AssetsTwo {
<% files.each do |path, var_name| -%>
    [Embed(source="<%= path %>")]
    public static var <%= var_name %>:Class;
<% end -%>
  }
}