dynamic_mapper.rb

class Array
  DYNAMIC_MAPPER_REGEXP = /^map_([_a-zA-Z]\w*)_to_([_a-zA-Z]\w*)$/
  
  def method_missing(method, *args, &block)
    dynamic_mapper?(method) do |match|
      map_dynamically(match[1], match[2])
    end || super
  end

  def dynamic_mapper?(method)
    yield Regexp.last_match if method.to_s =~ DYNAMIC_MAPPER_REGEXP
  end

  def map_dynamically(key, value)
    inject({}) do |result, hash|
      result.update(hash[key] => hash[value])
    end
  end
end

project_hashes = [{'name' => 'suspenders', 'color' => 'green'}, {'name' => 'shoulda', 'color' => 'green'}]
puts project_hashes.map_name_to_color.inspect