function command( repl ) {
	return onCommand;

	/**
	* Returns the result of the last successfully executed command.
	*
	* @private
	* @returns {*} result
	*/
	function onCommand() {
		return repl._ans;
	}
}
Returns a callback to be invoked upon calling the `ans` command.

@private
@param {REPL} repl - REPL instance
@returns {Function} callback