org.antlr.v4.runtime.tree.Tree Maven / Gradle / Ivy
/*
* [The "BSD license"]
* Copyright (c) 2012 Terence Parr
* Copyright (c) 2012 Sam Harwell
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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*/
package org.antlr.v4.runtime.tree;
import org.antlr.v4.runtime.RuleContext;
import org.antlr.v4.runtime.Token;
/** 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.
*/
public interface Tree {
/** The parent of this node. If the return value is null, then this
* node is the root of the tree.
*/
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.
*/
Object getPayload();
/** If there are children, get the {@code i}th value indexed from 0. */
Tree getChild(int i);
/** How many children are there? If there is none, then this
* node represents a leaf node.
*/
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.
*/
String toStringTree();
}