// Validation messages.
$messages = array(
	'empty'                                     => array(
		'positive' => sprintf(
			/* translators: 1: Type of a validation field. 2: Name of a validation field. */
			__( 'The %1$s %2$s is invalid and should be empty!', 'glotpress' ),
			$type_field,
			'<strong>' . $name_field . '</strong>'
		),
		'negative' => sprintf(
			/* translators: 1: Type of a validation field. 2: Name of a validation field. */
			__( 'The %1$s %2$s is invalid and should not be empty!', 'glotpress' ),
			$type_field,
			'<strong>' . $name_field . '</strong>'
		),
	),
	'empty_string'                              => array(
		'positive' => 'the positive message',
		'negative' => 'the negative message',
	),
	'positive_int'                              => array(
		'positive' => 'the positive message',
		'negative' => 'the negative message',
	),
	'int'                                       => array(
		'positive' => 'the positive message',
		'negative' => 'the negative message',
	),
	'null'                                      => array(
		'positive' => 'the positive message',
		'negative' => 'the negative message',
	),
	'between'                                   => array(
		'positive' => 'the positive message',
		'negative' => 'the negative message',
	),
	'between_exclusive'                         => array(
		'positive' => 'the positive message',
		'negative' => 'the negative message',
	),
	'one_of'                                    => array(
		'positive' => 'the positive message',
		'negative' => 'the negative message',
	),
	'consisting_only_of_ASCII_characters'       => array(
		'positive' => 'the positive message',
		'negative' => 'the negative message',
	),
	'starting_and_ending_with_a_word_character' => array(
		'positive' => 'the positive message',
		'negative' => 'the negative message',
	),
);

if ( 'positive' === $rule['kind'] ) {
	return $messages[ $rule['rule'] ]['positive'];
} else { // if ( 'negative' == $rule['kind'] )
	return $messages[ $rule['rule'] ]['negative'];
}