Upgrading from PHP-Parser 3.x to 4.0

PHP version requirements

PHP-Parser now requires PHP 7.0 or newer to run. It is however still possible to parse PHP 5.2-5.6 source code, while running on a newer version.

HHVM is no longer actively supported.

Changes to the node structure

• Many subnodes that previously held simple strings now store `Identifier` nodes instead (or `VarLikeIdentifier` nodes if they have form `$ident`). The constructors of the affected nodes will automatically convert strings to `Identifier`s and `Identifier`s implement `__toString()`. As such some code continues to work without changes, but anything using `is_string()`, type-strict comparisons or strict-mode may require adjustment. The following is an exhaustive list of all affected subnodes:

  * `Const_::$name` * `NullableType::$type` (for simple types) * `Param::$type` (for simple types) * `Expr\ClassConstFetch::$name` * `Expr\Closure::$returnType` (for simple types) * `Expr\MethodCall::$name` * `Expr\PropertyFetch::$name` * `Expr\StaticCall::$name` * `Expr\StaticPropertyFetch::$name` (uses `VarLikeIdentifier`) * `Stmt\Class_::$name` * `Stmt\ClassMethod::$name` * `Stmt\ClassMethod::$returnType` (for simple types) * `Stmt\Function_::$name` * `Stmt\Function_::$returnType` (for simple types) * `Stmt\Goto_::$name` * `Stmt\Interface_::$name` * `Stmt\Label::$name` * `Stmt\PropertyProperty::$name` (uses `VarLikeIdentifier`) * `Stmt\TraitUseAdaptation\Alias::$method` * `Stmt\TraitUseAdaptation\Alias::$newName` * `Stmt\TraitUseAdaptation\Precedence::$method` * `Stmt\Trait_::$name` * `Stmt\UseUse::$alias`

• Expression statements (`expr;`) are now represented using a `Stmt\Expression` node. Previously these statements were directly represented as their constituent expression.
• The `name` subnode of `Param` has been renamed to `var` and now contains a `Variable` rather than a plain string.
• The `name` subnode of `StaticVar` has been renamed to `var` and now contains a `Variable` rather than a plain string.
• The `var` subnode of `ClosureUse` now contains a `Variable` rather than a plain string.
• The `var` subnode of `Catch_` now contains a `Variable` rather than a plain string.
• The `alias` subnode of `UseUse` is now `null` if no explicit alias is given. As such, `use Foo\Bar` and `use Foo\Bar as Bar` are now represented differently. The `getAlias()` method can be used to get the effective alias, even if it is not explicitly given.

Miscellaneous

• The indentation handling in the pretty printer has been changed (this is only relevant if you extend the pretty printer). Previously indentation was automatic, and parts were excluded using `pNoindent()`. Now no-indent is the default and newlines that require indentation should use `$this->nl`.

Removed functionality

• Removed `type` subnode on `Class_`, `ClassMethod` and `Property` nodes. Use `flags` instead.
• The `ClassConst::isStatic()` method has been removed. Constants cannot have a static modifier.
• The `NodeTraverser` no longer accepts `false` as a return value from a `leaveNode()` method. `NodeTraverser::REMOVE_NODE` should be returned instead.
• The `Node::setLine()` method has been removed. If you really need to, you can use `setAttribute()` instead.
• The misspelled `Class_::VISIBILITY_MODIFER_MASK` constant has been dropped in favor of `Class_::VISIBILITY_MODIFIER_MASK`.
• The XML serializer has been removed. As such, the classes `Serializer\XML`, and `Unserializer\XML`, as well as the interfaces `Serializer` and `Unserializer` no longer exist.
• The `BuilderAbstract` class has been removed. It's functionality is moved into `BuilderHelpers`. However, this is an internal class and should not be used directly.
• The `Autoloader` class has been removed in favor of relying on the Composer autoloader.