This is a PHP 5.4 (and older) parser written in PHP. It's purpose is to simplify static code analysis and manipulation.
Documentation can be found in the
Note: This project is experimental, so the API is subject to change.
In a Nutshell
Basically, the parser does nothing more than turn some PHP code into an abstract syntax tree. ("nothing more" is kind of sarcastic here as PHP has a ... uhm, let's just say "not nice" ... grammar, which makes parsing PHP very hard.)
For example, if you stick this code in the parser:
<?php echo 'Hi', 'World'; hello\world('foo', 'bar' . 'baz');
You'll get a syntax tree looking roughly like this:
array( 0: Stmt_Echo( exprs: array( 0: Scalar_String( value: Hi ) 1: Scalar_String( value: World ) ) ) 1: Expr_FuncCall( name: Name( parts: array( 0: hello 1: world ) ) args: array( 0: Arg( value: Scalar_String( value: foo ) byRef: false ) 1: Arg( value: Expr_Concat( left: Scalar_String( value: bar ) right: Scalar_String( value: baz ) ) byRef: false ) ) ) )
You can then work with this syntax tree, for example to statically analyze the code (e.g. to find programming errors or security issues).
Additionally, you can convert a syntax tree back to PHP code. This allows you to do code preprocessing (like automatedly porting code to older PHP versions).
So, that's it, in a nutshell. You can find everything else in the docs.