+/**
+ * Implements a logic tree to determine whether or not "7'." represents seven feet,
+ * then converts the special char into either a prime char or a closing quote char.
+ *
+ * @since 4.3.0
+ *
+ * @param string $haystack The plain text to be searched.
+ * @param string $needle The character to search for such as ' or ".
+ * @param string $prime The prime char to use for replacement.
+ * @param string $open_quote The opening quote char. Opening quote replacement must be
+ * accomplished already.
+ * @param string $close_quote The closing quote char to use for replacement.
+ * @return string The $haystack value after primes and quotes replacements.
+ */
+function wptexturize_primes( $haystack, $needle, $prime, $open_quote, $close_quote ) {
+ $spaces = wp_spaces_regexp();
+ $flag = '<!--wp-prime-or-quote-->';
+ $quote_pattern = "/$needle(?=\\Z|[.,:;!?)}\\-\\]]|>|" . $spaces . ")/";
+ $prime_pattern = "/(?<=\\d)$needle/";
+ $flag_after_digit = "/(?<=\\d)$flag/";
+ $flag_no_digit = "/(?<!\\d)$flag/";
+
+ $sentences = explode( $open_quote, $haystack );
+
+ foreach( $sentences as $key => &$sentence ) {
+ if ( false === strpos( $sentence, $needle ) ) {
+ continue;
+ } elseif ( 0 !== $key && 0 === substr_count( $sentence, $close_quote ) ) {
+ $sentence = preg_replace( $quote_pattern, $flag, $sentence, -1, $count );
+ if ( $count > 1 ) {
+ // This sentence appears to have multiple closing quotes. Attempt Vulcan logic.
+ $sentence = preg_replace( $flag_no_digit, $close_quote, $sentence, -1, $count2 );
+ if ( 0 === $count2 ) {
+ // Try looking for a quote followed by a period.
+ $count2 = substr_count( $sentence, "$flag." );
+ if ( $count2 > 0 ) {
+ // Assume the rightmost quote-period match is the end of quotation.
+ $pos = strrpos( $sentence, "$flag." );
+ } else {
+ // When all else fails, make the rightmost candidate a closing quote.
+ // This is most likely to be problematic in the context of bug #18549.
+ $pos = strrpos( $sentence, $flag );
+ }
+ $sentence = substr_replace( $sentence, $close_quote, $pos, strlen( $flag ) );
+ }
+ // Use conventional replacement on any remaining primes and quotes.
+ $sentence = preg_replace( $prime_pattern, $prime, $sentence );
+ $sentence = preg_replace( $flag_after_digit, $prime, $sentence );
+ $sentence = str_replace( $flag, $close_quote, $sentence );
+ } elseif ( 1 == $count ) {
+ // Found only one closing quote candidate, so give it priority over primes.
+ $sentence = str_replace( $flag, $close_quote, $sentence );
+ $sentence = preg_replace( $prime_pattern, $prime, $sentence );
+ } else {
+ // No closing quotes found. Just run primes pattern.
+ $sentence = preg_replace( $prime_pattern, $prime, $sentence );
+ }
+ } else {
+ $sentence = preg_replace( $prime_pattern, $prime, $sentence );
+ $sentence = preg_replace( $quote_pattern, $close_quote, $sentence );
+ }
+ if ( '"' == $needle && false !== strpos( $sentence, '"' ) ) {
+ $sentence = str_replace( '"', $close_quote, $sentence );
+ }
+ }
+
+ return implode( $open_quote, $sentences );