Problem: I switched the language type to PHP and now I get wrong syntax highlight (or similar).

Short answer: Please switch back to using HTML as the language for your PHP files.

Long answer: PHP is short for PHP Hypertext Preprocessor, i.e. it is a preprocessor, it is not meant as a standalone language.

Quoting the manual:

> When PHP parses a file, it looks for opening and
> closing tags, which tell PHP to start and stop
> interpreting the code between them. Parsing in this
> manner allows php to be embedded in all sorts of
> different documents, as everything outside of a pair
> of opening and closing tags is ignored by the PHP
> parser. Most of the time you will see php embedded in
> HTML documents […]

So a document like the following is not PHP:

$var i = 42;

You must enclose that code in <?php … ?>. Even when you have a document like the following:

<?php include '' ?>

The include file is still HTML, again quoting the PHP manual:

> When a file is included, parsing drops out of PHP
> mode and into HTML mode at the beginning of the
> target file, and resumes again at the end. For this
> reason, any code inside the target file which should
> be executed as PHP code must be enclosed within valid
> PHP start and end tags.

For this reason we designed the HTML grammar to handle <?php … ?> tags and correctly switch to PHP mode when these tags are seen, as they are mandatory, and almost always found within HTML documents (which embed PHP).

We did not design PHP to be used as a stand-alone language, because from the above quotes, it is not a standalone language. It is always embedded into something else, and 99% of the time, that something else is HTML.