_some_partial.html.erb

<%# bar baz %>
You put your <%= bar %> in my <%= baz %>!

foo_helper.rb

module FooHelper
  include PartialMethods
end

index.html.erb

<%= p_some_partial("chocolate", "peanut butter") %>

partial_methods.rb

require 'find'
module PartialMethods
  def self.included(base)
    path = "#{Rails.root}/app/views/#{base.name.sub(/Helper$/,"").downcase}"
    Find.find(path) do |file|
      if file =~ /#{path}\/_(.+)/
        partial = $~[1].split(/\./)[0]

        required_arguments = []
        header = File.readlines(file)[0]
        if header =~ /^<%# +?(.*?) +?%>$/
          puts "header: #{header}"
          required_arguments = $~[1].split(/ +/)
        end

        method = Proc.new do |*args|
          if args.length != required_arguments.length 
            raise ArgumentError, "wrong number of arguments (#{args.length} for #{required_argumentss.length})"
          end
          options = {}
          required_arguments.each_with_index do |arg, i|
            options[arg.to_sym] = args[i]
          end
          render partial.to_s, options
        end
        define_method "p_#{partial}".to_sym, &method
      end
    end
  end
end