thegrandpoobah

_.mixin({
	// Polls condition indefinitely every N milliseconds and executes
	// a function once the condition has passed.
	retry: function(func, cond, wait) {
		var args = slice.call(arguments, 3);
		if (cond()) {
			func.apply(this, args);
		} else {
			_.delay.apply(this, [_.retry, wait, func, cond, wait].concat(args));
		}

rmcafee

class Hash
  def except(*blacklist)
    {}.tap do |h|
      (keys - blacklist).each { |k| h[k] = self[k] }
    end
  end

  def only(*whitelist)
    {}.tap do |h|
      (keys & whitelist).each { |k| h[k] = self[k] }