This is a PHP 5.2 to PHP 5.6 parser written in PHP. It's purpose is to simplify static code analysis and manipulation.

Documentation for version 1.0.x (stable; for running on PHP >= 5.3).

Documentation for version 0.9.x (unsupported; for running on PHP 5.2).

The parser turns PHP source code into an abstract syntax tree. For example, if you pass the following code into 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.