| // |
| // ANTLRTreeVisitor.m |
| // ANTLR |
| // |
| // Created by Alan Condit on 6/18/10. |
| // [The "BSD licence"] |
| // Copyright (c) 2010 Alan Condit |
| // 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. |
| |
| #import "ANTLRTreeVisitor.h" |
| #import "ANTLRCommonTreeAdaptor.h" |
| |
| @implementation ANTLRTreeVisitor |
| |
| + (ANTLRTreeVisitor *)newANTLRTreeVisitor:(id<ANTLRTreeAdaptor>)anAdaptor |
| { |
| return [[ANTLRTreeVisitor alloc] initWithAdaptor:anAdaptor]; |
| } |
| |
| + (ANTLRTreeVisitor *)newANTLRTreeVisitor |
| { |
| return [[ANTLRTreeVisitor alloc] init]; |
| } |
| |
| |
| - (id)init |
| { |
| if ((self = [super init]) != nil) { |
| adaptor = [[ANTLRCommonTreeAdaptor newTreeAdaptor] retain]; |
| } |
| return self; |
| } |
| |
| - (id)initWithAdaptor:(id<ANTLRTreeAdaptor>)anAdaptor |
| { |
| if ((self = [super init]) != nil) { |
| adaptor = [anAdaptor retain]; |
| } |
| return self; |
| } |
| |
| - (void) dealloc |
| { |
| #ifdef DEBUG_DEALLOC |
| NSLog( @"called dealloc in ANTLRTreeVisitor" ); |
| #endif |
| if ( adaptor ) [adaptor release]; |
| [super dealloc]; |
| } |
| |
| /** Visit every node in tree t and trigger an action for each node |
| * before/after having visited all of its children. |
| * Execute both actions even if t has no children. |
| * If a child visit yields a new child, it can update its |
| * parent's child list or just return the new child. The |
| * child update code works even if the child visit alters its parent |
| * and returns the new tree. |
| * |
| * Return result of applying post action to this node. |
| */ |
| - (ANTLRTreeVisitor *)visit:(ANTLRCommonTree *)t Action:(ANTLRTreeVisitorAction *)action |
| { |
| // System.out.println("visit "+((Tree)t).toStringTree()); |
| BOOL isNil = [adaptor isNil:t]; |
| if ( action != nil && !isNil ) { |
| t = [action pre:(ANTLRTreeVisitorAction *)t]; // if rewritten, walk children of new t |
| } |
| for (int i=0; i < [adaptor getChildCount:t]; i++) { |
| ANTLRCommonTree *child = [adaptor getChild:t At:i]; |
| ANTLRCommonTree *visitResult = [self visit:child Action:action]; |
| ANTLRCommonTree *childAfterVisit = [adaptor getChild:t At:i]; |
| if ( visitResult != childAfterVisit ) { // result & child differ? |
| [adaptor setChild:t At:i Child:visitResult]; |
| } |
| } |
| if ( action != nil && !isNil ) t = [action post:(ANTLRTreeVisitorAction *)t]; |
| return t; |
| } |
| |
| @synthesize adaptor; |
| @end |