protected function RegexCounter::findHellternations in Bibliography Module 7.2

Returns the hellternations which are siblings to each other. NOTE: the given $pattern is assumed to not contain escaped parentheses.

Parameters

string $pattern a string of alternations wrapped into (?|...):

Return value

array

Throws

RegexCounterException

1 call to RegexCounter::findHellternations()

RegexCounter::countGroups in lib/msrc-authortool/src/Nametools/RegexCounter.php

Returns how many groups (numbered or named) there are in the given $pattern

File

lib/msrc-authortool/src/Nametools/RegexCounter.php, line 126

Class

RegexCounter

Regexcounter is a class that counts the expected number of matches for a given REGEX pattern

Namespace

Nametools

Code

protected function findHellternations($pattern) {
  $result = array();
  $token = '(?|';
  $tokenLen = strlen($token);
  $offset = 0;
  do {
    $start = strpos($pattern, $token, $offset);
    if (FALSE === $start) {
      return $result;
    }
    $open = 1;
    $start += $tokenLen;
    for ($i = $start, $iTop = strlen($pattern); $i < $iTop; $i++) {

      //$current = $pattern[$i];
      if ($pattern[$i] == '(') {
        $open += 1;
      }
      elseif ($pattern[$i] == ')') {
        $open -= 1;
        if (0 == $open) {
          $result[$start] = substr($pattern, $start, $i - $start);
          $offset = $i + 1;
          break;
        }
      }
    }
  } while ($i < $iTop);
  if (0 != $open) {
    throw new RegexCounterException('Unbalanced parentheses.');
  }
  return $result;
}