1 // [The "BSD licence"] 2 // Copyright (c) 2006-2007 Kay Roepke 3 // All rights reserved. 4 // 5 // Redistribution and use in source and binary forms, with or without 6 // modification, are permitted provided that the following conditions 7 // are met: 8 // 1. Redistributions of source code must retain the above copyright 9 // notice, this list of conditions and the following disclaimer. 10 // 2. Redistributions in binary form must reproduce the above copyright 11 // notice, this list of conditions and the following disclaimer in the 12 // documentation and/or other materials provided with the distribution. 13 // 3. The name of the author may not be used to endorse or promote products 14 // derived from this software without specific prior written permission. 15 // 16 // THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 17 // IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18 // OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19 // IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 20 // INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 21 // NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 22 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 23 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 25 // THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 27 28 #import <Foundation/Foundation.h> 29 #import "IntStream.h" 30 #import "CharStream.h" 31 #import "TokenStream.h" 32 #import "CommonTree.h" 33 #import "CommonTreeAdaptor.h" 34 35 @protocol TreeNodeStream < IntStream > 36 37 - (id) initWithTree:(CommonTree *)theTree; 38 39 /** Get a tree node at an absolute index i; 0..n-1. 40 * If you don't want to buffer up nodes, then this method makes no 41 * sense for you. 42 */ 43 - (id) get:(NSInteger) idx; 44 /** Get tree node at current input pointer + i ahead where i=1 is next node. 45 * i<0 indicates nodes in the past. So LT(-1) is previous node, but 46 * implementations are not required to provide results for k < -1. 47 * LT(0) is undefined. For i>=n, return null. 48 * Return null for LT(0) and any index that results in an absolute address 49 * that is negative. 50 * 51 * This is analogus to the LT() method of the TokenStream, but this 52 * returns a tree node instead of a token. Makes code gen identical 53 * for both parser and tree grammars. :) 54 */ 55 - (id) LT:(NSInteger)k; 56 /** Where is this stream pulling nodes from? This is not the name, but 57 * the object that provides node objects. 58 */ 59 - (id) getTreeSource; 60 /** If the tree associated with this stream was created from a TokenStream, 61 * you can specify it here. Used to do rule $text attribute in tree 62 * parser. Optional unless you use tree parser rule text attribute 63 * or output=template and rewrite=true options. 64 */ 65 - (id<TokenStream>) getTokenStream; 66 /** What adaptor can tell me how to interpret/navigate nodes and 67 * trees. E.g., get text of a node. 68 */ 69 - (id<TreeAdaptor>) getTreeAdaptor; 70 /** As we flatten the tree, we use UP, DOWN nodes to represent 71 * the tree structure. When debugging we need unique nodes 72 * so we have to instantiate new ones. When doing normal tree 73 * parsing, it's slow and a waste of memory to create unique 74 * navigation nodes. Default should be false; 75 */ 76 - (void) setUniqueNavigationNodes:(BOOL)flag; 77 /** Reset the tree node stream in such a way that it acts like 78 * a freshly constructed stream. 79 */ 80 - (void) reset; 81 82 /** Return the text of all nodes from start to stop, inclusive. 83 * If the stream does not buffer all the nodes then it can still 84 * walk recursively from start until stop. You can always return 85 * null or "" too, but users should not access $ruleLabel.text in 86 * an action of course in that case. 87 */ 88 - (NSString *) toStringFromNode:(id)startNode ToNode:(id)stopNode; 89 90 /** Replace from start to stop child index of parent with t, which might 91 * be a list. Number of children may be different 92 * after this call. The stream is notified because it is walking the 93 * tree and might need to know you are monkeying with the underlying 94 * tree. Also, it might be able to modify the node stream to avoid 95 * restreaming for future phases. 96 * 97 * If parent is null, don't do anything; must be at root of overall tree. 98 * Can't replace whatever points to the parent externally. Do nothing. 99 */ 100 - (void) replaceChildren:(id)parent From:(NSInteger)startChildIndex To:(NSInteger)stopChildIndex With:(id) t; 101 102 103 @end 104