/*!
  @header ECStack
  @abstract Module of Encore
 
  @availability OS X, GNUstep
  @copyright 2004, 2005, 2006 Oliver Langer

  Author: Oliver Langer

  This library is free software; you can redistribute it and/or
  modify it under the terms of the GNU Lesser General Public
  License as published by the Free Software Foundation; either
  version 2.1 of the License, or (at your option) any later version.

  This library is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  Lesser General Public License for more details.

  You should have received a copy of the GNU Lesser General Public
  License along with this library; if not, write to the Free Software
  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA

  <pre>
  -------------------------------------------------------------------------
  Modification history

  25.06.05 ola     initial version
  22.08.06 ola     license changed
  -------------------------------------------------------------------------
  </pre>
*/

#include <Encore/ECStack.h>
#include <Encore/ECExceptions.h>

@implementation ECStack

- init {
  self = [super init];
  self->lock = [[NSLock alloc] init];
  self->stackData = [[NSMutableArray alloc] init];
  
  return self;
}


- (void) dealloc {
  [self->lock release];
  [self->stackData release];
  
  [super dealloc];
}


- (unsigned) count {
  return [self->stackData count];
}


- (BOOL) isEmpty {
  return [self count] == 0;
}


- (BOOL) isEqual: (id) anObject {
  BOOL equals = NO;
  if( nil != anObject ) {
    if( [anObject isKindOfClass: [self class]] ) {      
      equals = [self->stackData isEqual: ((ECStack *) anObject)->stackData];
    }
  }
  
  return equals;
}


- popObject {
  id toReturn = nil;
  
  [self->lock lock];

  toReturn = [[self->stackData lastObject] retain];
  if( nil != toReturn ) {
    NS_DURING
      [self->stackData removeLastObject];
    NS_HANDLER
      [self->lock release];
      [localException raise];
    NS_ENDHANDLER
  }
  [self->lock unlock];
  
  return [toReturn autorelease];
}


- pushObject: (id) toPush {
  if( nil == toPush ) {
    [[[ECIllegalArgumentException alloc]
      initWithArgumentInfo: @"Cannot push nil"] raise];
  }
  
  [self->lock lock];
  [self->stackData addObject: toPush];
  [self->lock unlock];
  
  return self;
}


- topObject {
  return [self->stackData lastObject];
}


@end