PHP7 AST exporer

The API

class AstKit {
  // All ZEND_AST_* enums are registered as constants
  const int ZEND_AST_* = *;

  /**
   * Option to parseString/parseFile
   *
   * Disable any zend_ast_hook
   * which may have been registered
   * by another extension
   */
  const int NO_PROCESS = 1;

  /**
   * You don't new these objects.
   * See AstKit::parseString() and AstKit::parseFile()
   * as well as various get*() methods
   */
  private function __construct();

  /**
   * Translate a ZEND_AST_* enum to its human readable name
   */
  static public function kindName(int $kind): string;

  /**
   * Generate an AST from a PHP string
   */
  static public function parseString(string $code,
                                     int $options = 0): ?AstKit;

  /**
   * Generate an AST from a PHP file
   */
  static public function parseFile(string $filename,
                                   int $options = 0): ?AstKit;

  /**
   * Graft an AST subtree into position
   * @param int $child - Child number to graft onto, existing node will be destroyed
   * @param mixed $treeOrValue - AstKit node or ZEND_AST_ZVAL value to emplace
   */
  public function graft(int $child, $treeOrValue): void;

  /**
   * Execute the current AST fragment
   * @return - Result of fragment execution, as though it had been eval()'d
   */
  public function execute(): mixed;

  /**
   * Get the ZEND_AST_* kind associated with this node
   */
  public function getId(): int;

  /**
   * Get the attributes for this node
   */
  public function getAttributes(): int;

  /**
   * Get the line this AST node appeared on
   */
  public function getLine(): int;

  /**
   * How many children does this node have?
   */
  public function numChildren(): int;

  /**
   * Get one of this node's children [0, numChildren() - 1]
   * @param int $child - Child to fetch
   * @param bool $asValue - Whether or not to return simple PHP values (true) or instances of AstKitZval (false)
   */
  public function getChild(int $child, bool $asValue = true);
}

/**
 * Specialization of AstKit for List style nodes
 *
 * The API is the same as AstKit,
 * but there are internal differences which make
 * having a separate class better
 *
 * Note that while numChildren/getChild can be used
 * Declarations have specific child layouts,
 * so the hasX()/getX() may be more useful
 * and less brittle.
 */
class AstKitList extends AstKit {
  /**
   * Create a new, empty ZEND_AST_STMT_LIST node
   */
  public function __construct();
}

/**
 * Specialization of AstKit for declarations
 */
class AstKitDecl extends AstKit {
  /**
   * Line number on which the declaration ends
   */
  public function getLineEnd(): int;

  /**
   * Declaration specific flags
   */
  public function getFlags(): int;

  /**
   * The Doc Comment, duh...
   */
  public function getDocComment(): string;

  /**
   * The name of the thing being declared
   */
  public function getName(): string;

  /**
   * Is there a parameter list for this function/method
   */
  public function hasParams(): bool;

  /**
   * Get the parameter list
   */
  public function getParams(): ?AstKit;

  /**
   * Are there use variable bound to this closure?
   */
  public function hasUse(): bool;

  /**
   * Get the use list
   */
  public function getUse(): ?AstKit;

  /**
   * Are there statements associated with this declaration
   */
  public function hasStatements(): bool;

  /**
   * Get the statements associated with this declaration
   */
  public function getStatements(): ?AstKit;
}

class AstKitZval extends AstKit {
  /**
   * Returns the PHP Value for this ZEND_AST_ZVAL node
   */
  public function getValue();
}