Section separators in mustache.rb

sep.rb

require 'mustache'
require 'yaml'

class Sep < Mustache
  def last?
    self[:to_s] == self[:names].last.to_s
  end
end

template = <<template
Gem Names:
* {{#names}}{{to_s}}{{^last?}}{{separator}}{{/last?}}{{/names}}{{! hack}}
* {{#names}}{{to_s}}{{^last?}}, {{/last?}}{{/names}}{{! hack}}
template

data = YAML.load(<<yaml)
names: [ mustache, sinatra, rack]
separator: " - "
yaml

puts Sep.render(template, data)

sep_output

$ ruby sep.rb 
Gem Names:
* mustache - sinatra - rack
* mustache, sinatra, rack