private function _yield() {
    $node = new YieldNode();
    $this->mustMatch(T_YIELD, $node);
    $expr = $this->expr();
    if ($this->tryMatch(T_DOUBLE_ARROW, $node)) {
      $node->addChild($expr, 'key');
      $node->addChild($this->expr(), 'value');
    }
    else {
      $node->addChild($expr, 'value');
    }
    return $node;
  }
private function _yield() {
    $node = new YieldNode();
    $this->mustMatch(T_YIELD, $node);
    $expr = $this->expr();
    if ($this->tryMatch(T_DOUBLE_ARROW, $node)) {
      $node->addChild($expr, 'key');
      $node->addChild($this->expr(), 'value');
    }
    else {
      $node->addChild($expr, 'value');
    }
    return $node;
  }
private function _yield ( ) { $ node = new YieldNode ( ) ; $ this -> mustMatch ( T_YIELD , $ node ) ; $ expr = $ this -> expr ( ) ; if ( $ this -> tryMatch ( T_DOUBLE_ARROW , $ node ) ) { $ node -> addChild ( $ expr , 'key' ) ; $ node -> addChild ( $ this -> expr ( ) , 'value' ) ; } else { $ node -> addChild ( $ expr , 'value' ) ; } return $ node ; }
Parse a yield expression.
@return YieldNode
Parse a yield expression .