/* * Copyright (c) 2012-2018 The ANTLR Project. All rights reserved. * Use of this file is governed by the BSD 3-clause license that * can be found in the LICENSE.txt file in the project root. */ module antlr.v4.runtime.tree.Tree; /** * The basic notion of a tree has a parent, a payload, and a list of children. * It is the most abstract interface for all the trees used by ANTLR. */ interface Tree { /** * The parent of this node. If the return value is null, then this * node is the root of the tree. */ public Tree getParent(); /** * This method returns whatever object represents the data at this note. For * example, for parse trees, the payload can be a {@link Token} representing * a leaf node or a {@link RuleContext} object representing a rule * invocation. For abstract syntax trees (ASTs), this is a {@link Token} * object. */ public Object getPayload(); /** * If there are children, get the {@code i}th value indexed from 0. */ public Tree getChild(int i); /** * How many children are there? If there is none, then this * node represents a leaf node. */ public int getChildCount(); /** * Print out a whole tree, not just a node, in LISP format * {@code (root child1 .. childN)}. Print just a node if this is a leaf. */ public string toStringTree(); }