88 public function pop() {
89 if ( $this->stack === [] ) {
90 throw new RuntimeException( __METHOD__ .
': no elements remaining' );
92 $temp = array_pop( $this->stack );
94 if (
count( $this->stack ) ) {
95 $this->top = $this->stack[
count( $this->stack ) - 1];
96 $this->accum =& $this->top->getAccum();