Example YAML template for Net on #ruby channel IRC

erb.rb

require 'erb'
require 'psych'

topic = :users
users = %w[wombat fox poodle]

template = ERB.new <<~END, trim_mode: '-'
---
:<%= topic %>:
<%- users.each do |user| %>
- <%= user %>
<%- end %>
END

yaml = template.result binding
#=> "---\n:users:\n\n- wombat\n\n- fox\n\n- poodle\n\n"

Psych.safe_load(yaml, permitted_classes: [Symbol])
#=> {:users=>["wombat", "fox", "poodle"]}