Chris@0: Upgrading from PHP-Parser 1.x to 2.0
Chris@0: ====================================
Chris@0: 
Chris@0: ### PHP version requirements
Chris@0: 
Chris@0: PHP-Parser now requires PHP 5.4 or newer to run. It is however still possible to *parse* PHP 5.2 and
Chris@0: PHP 5.3 source code, while running on a newer version.
Chris@0: 
Chris@0: ### Creating a parser instance
Chris@0: 
Chris@0: Parser instances should now be created through the `ParserFactory`. Old direct instantiation code
Chris@0: will not work, because the parser class was renamed.
Chris@0: 
Chris@0: Old:
Chris@0: 
Chris@0: ```php
Chris@0: use PhpParser\Parser, PhpParser\Lexer;
Chris@0: $parser = new Parser(new Lexer\Emulative);
Chris@0: ```
Chris@0: 
Chris@0: New:
Chris@0: 
Chris@0: ```php
Chris@0: use PhpParser\ParserFactory;
Chris@0: $parser = (new ParserFactory)->create(ParserFactory::PREFER_PHP7);
Chris@0: ```
Chris@0: 
Chris@0: The first argument to `ParserFactory` determines how different PHP versions are handled. The
Chris@0: possible values are:
Chris@0: 
Chris@0:  * `ParserFactory::PREFER_PHP7`: Try to parse code as PHP 7. If this fails, try to parse it as PHP 5.
Chris@0:  * `ParserFactory::PREFER_PHP5`: Try to parse code as PHP 5. If this fails, try to parse it as PHP 7.
Chris@0:  * `ParserFactory::ONLY_PHP7`: Parse code as PHP 7.
Chris@0:  * `ParserFactory::ONLY_PHP5`: Parse code as PHP 5.
Chris@0: 
Chris@0: For most practical purposes the difference between `PREFER_PHP7` and `PREFER_PHP5` is mainly whether
Chris@0: a scalar type hint like `string` will be stored as `'string'` (PHP 7) or as `new Name('string')`
Chris@0: (PHP 5).
Chris@0: 
Chris@0: To use a custom lexer, pass it as the second argument to the `create()` method:
Chris@0: 
Chris@0: ```php
Chris@0: use PhpParser\ParserFactory;
Chris@0: $lexer = new MyLexer;
Chris@0: $parser = (new ParserFactory)->create(ParserFactory::PREFER_PHP7, $lexer);
Chris@0: ```
Chris@0: 
Chris@0: ### Rename of the `PhpParser\Parser` class
Chris@0: 
Chris@0: `PhpParser\Parser` is now an interface, which is implemented by `Parser\Php5`, `Parser\Php7` and
Chris@0: `Parser\Multiple`. Parser tokens are now defined in `Parser\Tokens`. If you use the `ParserFactory`
Chris@0: described above to create your parser instance, these changes should have no further impact on you.
Chris@0: 
Chris@0: ### Removal of legacy aliases
Chris@0: 
Chris@0: All legacy aliases for classes have been removed. This includes the old non-namespaced `PHPParser_`
Chris@0: classes, as well as the classes that had to be renamed for PHP 7 support.
Chris@0: 
Chris@0: ### Deprecations
Chris@0: 
Chris@0: The `set()`, `setFirst()`, `append()` and `prepend()` methods of the `Node\Name` class have been
Chris@0: deprecated. Instead `Name::concat()` and `Name->slice()` should be used.
Chris@0: 
Chris@0: ### Miscellaneous
Chris@0: 
Chris@0: * The `NodeTraverser` no longer clones nodes by default. If you want to restore the old behavior,
Chris@0:   pass `true` to the constructor.
Chris@0: * The legacy node format has been removed. If you use custom nodes, they are now expected to
Chris@0:   implement a `getSubNodeNames()` method.
Chris@0: * The default value for `Scalar` node constructors was removed. This means that something like
Chris@0:   `new LNumber()` should be replaced by `new LNumber(0)`.
Chris@0: * String parts of encapsed strings are now represented using `Scalar\EncapsStringPart` nodes, while
Chris@0:   previously raw strings were used. This affects the `parts` child of `Scalar\Encaps` and
Chris@0:   `Expr\ShellExec`.