php_parser.php
protected function addInTagTokens()
    {
        $this->mapHandler('tag', 'acceptStartToken');
        $this->addSpecialPattern('\s+', 'tag', 'ignore');
        $this->addAttributeTokens();
        $this->addExitPattern('/>', 'tag');
        $this->addExitPattern('>', 'tag');
    }
protected function addInTagTokens()
    {
        $this->mapHandler('tag', 'acceptStartToken');
        $this->addSpecialPattern('\s+', 'tag', 'ignore');
        $this->addAttributeTokens();
        $this->addExitPattern('/>', 'tag');
        $this->addExitPattern('>', 'tag');
    }
Pattern matches to parse the inside of a tag including the attributes and their quoting.