function smilies_init() {
  global $wpsmiliestrans, $wp_smiliessearch;

  // Don't bother setting up smilies if they are disabled.
  if ( ! get_option( 'use_smilies' ) ) {
    return;
  }

  if ( ! isset( $wpsmiliestrans ) ) {
    $wpsmiliestrans = array(
      ':mrgreen:' => 'mrgreen.png',
      ':neutral:' => "\xf0\x9f\x98\x90",
      ':twisted:' => "\xf0\x9f\x98\x88",
      ':arrow:'   => "\xe2\x9e\xa1",
      ':shock:'   => "\xf0\x9f\x98\xaf",
      ':smile:'   => "\xf0\x9f\x99\x82",
      ':???:'     => "\xf0\x9f\x98\x95",
      ':cool:'    => "\xf0\x9f\x98\x8e",
      ':evil:'    => "\xf0\x9f\x91\xbf",
      ':grin:'    => "\xf0\x9f\x98\x80",
      ':idea:'    => "\xf0\x9f\x92\xa1",
      ':oops:'    => "\xf0\x9f\x98\xb3",
      ':razz:'    => "\xf0\x9f\x98\x9b",
      ':roll:'    => "\xf0\x9f\x99\x84",
      ':wink:'    => "\xf0\x9f\x98\x89",
      ':cry:'     => "\xf0\x9f\x98\xa5",
      ':eek:'     => "\xf0\x9f\x98\xae",
      ':lol:'     => "\xf0\x9f\x98\x86",
      ':mad:'     => "\xf0\x9f\x98\xa1",
      ':sad:'     => "\xf0\x9f\x99\x81",
      '8-)'       => "\xf0\x9f\x98\x8e",
      '8-O'       => "\xf0\x9f\x98\xaf",
      ':-('       => "\xf0\x9f\x99\x81",
      ':-)'       => "\xf0\x9f\x99\x82",
      ':-?'       => "\xf0\x9f\x98\x95",
      ':-D'       => "\xf0\x9f\x98\x80",
      ':-P'       => "\xf0\x9f\x98\x9b",
      ':-o'       => "\xf0\x9f\x98\xae",
      ':-x'       => "\xf0\x9f\x98\xa1",
      ':-|'       => "\xf0\x9f\x98\x90",
      ';-)'       => "\xf0\x9f\x98\x89",
      // This one transformation breaks regular text with frequency.
      //     '8)' => "\xf0\x9f\x98\x8e",
      '8O'        => "\xf0\x9f\x98\xaf",
      ':('        => "\xf0\x9f\x99\x81",
      ':)'        => "\xf0\x9f\x99\x82",
      ':?'        => "\xf0\x9f\x98\x95",
      ':D'        => "\xf0\x9f\x98\x80",
      ':P'        => "\xf0\x9f\x98\x9b",
      ':o'        => "\xf0\x9f\x98\xae",
      ':x'        => "\xf0\x9f\x98\xa1",
      ':|'        => "\xf0\x9f\x98\x90",
      ';)'        => "\xf0\x9f\x98\x89",
      ':!:'       => "\xe2\x9d\x97",
      ':?:'       => "\xe2\x9d\x93",
    );
  }

  
/**
 * Filters all the smilies.
 *
 * This filter must be added before `smilies_init` is run, as
 * it is normally only run once to setup the smilies regex.
 *
 * @since 4.7.0
 *
 * @param string[] $wpsmiliestrans List of the smilies' hexadecimal representations, keyed by their smily code.
 */
  $wpsmiliestrans = apply_filters( 'smilies', $wpsmiliestrans );

  if ( count( $wpsmiliestrans ) === 0 ) {
    return;
  }

  /*
	 * NOTE: we sort the smilies in reverse key order. This is to make sure
	 * we match the longest possible smilie (:???: vs :?) as the regular
	 * expression used below is first-match
	 */
  krsort( $wpsmiliestrans );

  $spaces = wp_spaces_regexp();

  // Begin first "subpattern".
  $wp_smiliessearch = '/(?<=' . $spaces . '|^)';

  $subchar = '';
  foreach ( (array) $wpsmiliestrans as $smiley => $img ) {
    $firstchar = substr( $smiley, 0, 1 );
    $rest      = substr( $smiley, 1 );

    // New subpattern?
    if ( $firstchar !== $subchar ) {
      if ( '' !== $subchar ) {
        $wp_smiliessearch .= ')(?=' . $spaces . '|$)';  // End previous "subpattern".
        $wp_smiliessearch .= '|(?<=' . $spaces . '|^)'; // Begin another "subpattern".
      }

      $subchar           = $firstchar;
      $wp_smiliessearch .= preg_quote( $firstchar, '/' ) . '(?:';
    } else {
      $wp_smiliessearch .= '|';
    }

    $wp_smiliessearch .= preg_quote( $rest, '/' );
  }

  $wp_smiliessearch .= ')(?=' . $spaces . '|$)/m';
}