This is a PHP 5.2 to PHP 7.4 parser written in PHP. Its purpose is to simplify static code analysis and manipulation.

Documentation for version 4.x (stable; for running on PHP >= 7.0; for parsing PHP 5.2 to PHP 7.4).

Documentation for version 3.x (unsupported; for running on PHP >= 5.5; for parsing PHP 5.2 to PHP 7.2).

The main features provided by this library are:

• Parsing PHP 5 and PHP 7 code into an abstract syntax tree (AST).
  • Invalid code can be parsed into a partial AST.
  • The AST contains accurate location information.
• Dumping the AST in human-readable form.
• Converting an AST back to PHP code.
  • Experimental: Formatting can be preserved for partially changed ASTs.
• Infrastructure to traverse and modify ASTs.
• Resolution of namespaced names.
• Evaluation of constant expressions.
• Builders to simplify AST construction for code generation.
• Converting an AST into JSON and back.

Install the library using composer:

php composer.phar require nikic/php-parser 

Parse some PHP code into an AST and dump the result in human-readable form:

<?php use PhpParser\Error; use PhpParser\NodeDumper; use PhpParser\ParserFactory; $code = <<<'CODE' <?php  function test($foo) {  var_dump($foo); } CODE; $parser = (new ParserFactory)->create(ParserFactory::PREFER_PHP7); try { $ast = $parser->parse($code); } catch (Error $error) { echo "Parse error: {$error->getMessage()}\n"; return; } $dumper = new NodeDumper; echo $dumper->dump($ast) . "\n";

This dumps an AST looking something like this:

array( 0: Stmt_Function( byRef: false name: Identifier( name: test ) params: array( 0: Param( type: null byRef: false variadic: false var: Expr_Variable( name: foo ) default: null ) ) returnType: null stmts: array( 0: Stmt_Expression( expr: Expr_FuncCall( name: Name( parts: array( 0: var_dump ) ) args: array( 0: Arg( value: Expr_Variable( name: foo ) byRef: false unpack: false ) ) ) ) ) ) ) 

Let's traverse the AST and perform some kind of modification. For example, drop all function bodies:

use PhpParser\Node; use PhpParser\Node\Stmt\Function_; use PhpParser\NodeTraverser; use PhpParser\NodeVisitorAbstract; $traverser = new NodeTraverser(); $traverser->addVisitor(new class extends NodeVisitorAbstract { public function enterNode(Node $node) { if ($node instanceof Function_) { // Clean out the function body $node->stmts = []; } } }); $ast = $traverser->traverse($ast); echo $dumper->dump($ast) . "\n";

This gives us an AST where the Function_::$stmts are empty:

array( 0: Stmt_Function( byRef: false name: Identifier( name: test ) params: array( 0: Param( type: null byRef: false variadic: false var: Expr_Variable( name: foo ) default: null ) ) returnType: null stmts: array( ) ) ) 

Finally, we can convert the new AST back to PHP code:

use PhpParser\PrettyPrinter; $prettyPrinter = new PrettyPrinter\Standard; echo $prettyPrinter->prettyPrintFile($ast);

This gives us our original code, minus the var_dump() call inside the function:

<?php function test($foo) { }

For a more comprehensive introduction, see the documentation.

1. Introduction
2. Usage of basic components

Component documentation:

• Walking the AST
  • Node visitors
  • Modifying the AST from a visitor
  • Short-circuiting traversals
  • Interleaved visitors
  • Simple node finding API
  • Parent and sibling references
• Name resolution
  • Name resolver options
  • Name resolution context
• Pretty printing
  • Converting AST back to PHP code
  • Customizing formatting
  • Formatting-preserving code transformations
• AST builders
  • Fluent builders for AST nodes
• Lexer
  • Lexer options
  • Token and file positions for nodes
  • Custom attributes
• Error handling
  • Column information for errors
  • Error recovery (parsing of syntactically incorrect code)
• Constant expression evaluation
  • Evaluating constant/property/etc initializers
  • Handling errors and unsupported expressions
• JSON representation
  • JSON encoding and decoding of ASTs
• Performance
  • Disabling XDebug
  • Reusing objects
  • Garbage collection impact
• Frequently asked questions
  • Parent and sibling references