runtime/ObjC/Framework/TreeVisitorAction.h

//
//  TreeVisitorAction.h
//  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 <Foundation/Foundation.h>
#import "BaseTree.h"

@interface TreeVisitorAction : NSObject
{
    SEL preAction;
    SEL postAction;

}

@property (assign, setter=setPreAction:) SEL preAction;
@property (assign, setter=setPostAction:) SEL postAction;

+ (TreeVisitorAction *)newTreeVisitorAction;
- (id) init;

- (void)setPreAction:(SEL)anAction;
- (void)setPostAction:(SEL)anAction;

/** Execute an action before visiting children of t.  Return t or
 *  a rewritten t.  It is up to the visitor to decide what to do
 *  with the return value.  Children of returned value will be
 *  visited if using TreeVisitor.visit().
 */
- (id<BaseTree>)pre:(id<BaseTree>) t;

/** Execute an action after visiting children of t.  Return t or
 *  a rewritten t.  It is up to the visitor to decide what to do
 *  with the return value.
 */
- (id<BaseTree>)post:(id<BaseTree>) t;

@end

@class TreeFilter;
@class fptr;

@interface TreeVisitorActionFiltered : TreeVisitorAction
{
    TreeFilter *aTFilter;
    fptr *TDRule;
    fptr *BURule;
}

@property (assign, setter=setATFilter:) TreeFilter *aTFilter;

+ (TreeVisitorAction *)newTreeVisitorActionFiltered:(TreeFilter *)aFilter RuleD:(fptr *)aTDRule RuleU:(fptr *)aBURule;
- (id) initWithFilter:(TreeFilter *)aFilter RuleD:(fptr *)aTDRule RuleU:(fptr *)aBURule;

/** Execute an action before visiting children of t.  Return t or
 *  a rewritten t.  It is up to the visitor to decide what to do
 *  with the return value.  Children of returned value will be
 *  visited if using TreeVisitor.visit().
 */
- (id<BaseTree>)pre:(id<BaseTree>) t;

/** Execute an action after visiting children of t.  Return t or
 *  a rewritten t.  It is up to the visitor to decide what to do
 *  with the return value.
 */
- (id<BaseTree>)post:(id<BaseTree>) t;

@end