| /* |
| [The "BSD license"] |
| Copyright (c) 2005-2009 Terence Parr |
| 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 |
| THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| package org.antlr.runtime.tree; |
| |
| import org.antlr.runtime.IntStream; |
| import org.antlr.runtime.TokenStream; |
| |
| /** A stream of tree nodes, accessing nodes from a tree of some kind */ |
| public interface TreeNodeStream extends IntStream { |
| /** Get a tree node at an absolute index i; 0..n-1. |
| * If you don't want to buffer up nodes, then this method makes no |
| * sense for you. |
| */ |
| public Object get(int i); |
| |
| /** Get tree node at current input pointer + i ahead where i=1 is next node. |
| * i<0 indicates nodes in the past. So LT(-1) is previous node, but |
| * implementations are not required to provide results for k < -1. |
| * LT(0) is undefined. For i>=n, return null. |
| * Return null for LT(0) and any index that results in an absolute address |
| * that is negative. |
| * |
| * This is analogus to the LT() method of the TokenStream, but this |
| * returns a tree node instead of a token. Makes code gen identical |
| * for both parser and tree grammars. :) |
| */ |
| public Object LT(int k); |
| |
| /** Where is this stream pulling nodes from? This is not the name, but |
| * the object that provides node objects. |
| */ |
| public Object getTreeSource(); |
| |
| /** If the tree associated with this stream was created from a TokenStream, |
| * you can specify it here. Used to do rule $text attribute in tree |
| * parser. Optional unless you use tree parser rule text attribute |
| * or output=template and rewrite=true options. |
| */ |
| public TokenStream getTokenStream(); |
| |
| /** What adaptor can tell me how to interpret/navigate nodes and |
| * trees. E.g., get text of a node. |
| */ |
| public TreeAdaptor getTreeAdaptor(); |
| |
| /** As we flatten the tree, we use UP, DOWN nodes to represent |
| * the tree structure. When debugging we need unique nodes |
| * so we have to instantiate new ones. When doing normal tree |
| * parsing, it's slow and a waste of memory to create unique |
| * navigation nodes. Default should be false; |
| */ |
| public void setUniqueNavigationNodes(boolean uniqueNavigationNodes); |
| |
| /** Reset the tree node stream in such a way that it acts like |
| * a freshly constructed stream. |
| */ |
| public void reset(); |
| |
| /** Return the text of all nodes from start to stop, inclusive. |
| * If the stream does not buffer all the nodes then it can still |
| * walk recursively from start until stop. You can always return |
| * null or "" too, but users should not access $ruleLabel.text in |
| * an action of course in that case. |
| */ |
| public String toString(Object start, Object stop); |
| |
| |
| // REWRITING TREES (used by tree parser) |
| |
| /** Replace from start to stop child index of parent with t, which might |
| * be a list. Number of children may be different |
| * after this call. The stream is notified because it is walking the |
| * tree and might need to know you are monkeying with the underlying |
| * tree. Also, it might be able to modify the node stream to avoid |
| * restreaming for future phases. |
| * |
| * If parent is null, don't do anything; must be at root of overall tree. |
| * Can't replace whatever points to the parent externally. Do nothing. |
| */ |
| public void replaceChildren(Object parent, int startChildIndex, int stopChildIndex, Object t); |
| } |