Stack class for Cocoa?

Michael Ash wrote:
> Lorenzo Thurman wrote:
>> Is there no stack class or equiv in Cocoa? Do I have to roll my own?
>> I'll probably just use an array, unless there are better suggestions.
>
> NSMutableArray will do the job just fine. Push is addObject:, pop is a
> lastObject followed by a removeLastObject. (Remember to either finish
> using the object or retain it before the remove.) There's no point in
> having a separate stack class when an existing one will do. You can do
> similar things to use them as a queue.
>
> If you find yourself doing this a lot, adding push/pop methods in a
> category could be useful.
>
A mutable one of course. I'd already done the methods, they were trivial
enough. What I hadn't thought about was just adding the methods via a
category.
Questions are powerful tools.
Thanks for the reply.

In article ,
Lorenzo Thurman wrote:

> Is there no stack class or equiv in Cocoa? Do I have to roll my own?
> I'll probably just use an array, unless there are better suggestions.
> TIA

Use a mutable array. It doesn't enforce stack-like behavior, but it's
trivial to add things to the end, retrieve the last item and remove the
last item. You could even make it a category.

-------------8<---------------------------

#warning Typed into news reader.

@interface NSMutableArray (GWStack)
- (void)push:(id)inObject;
- (id)pop;
@end

@implementation NSMutableArray (GWStack)

- (void)push:(id)inObject
{
if(inObject) [self addObject:inObject];
}

- (id)pop
{
id theResult = nil;
if([self count])
{
theResult = [[[self lastObject] retain] autorelease];
[self removeLastObject];
}
return theResult;
}

@end

Gregory Weston wrote:
> In article ,
> Lorenzo Thurman wrote:
>
>> Is there no stack class or equiv in Cocoa? Do I have to roll my own?
>> I'll probably just use an array, unless there are better suggestions.
>> TIA
>
> Use a mutable array. It doesn't enforce stack-like behavior, but it's
> trivial to add things to the end, retrieve the last item and remove the
> last item. You could even make it a category.
>
> -------------8<---------------------------
>
> #warning Typed into news reader.
>
> @interface NSMutableArray (GWStack)
> - (void)push:(id)inObject;
> - (id)pop;
> @end
>
> @implementation NSMutableArray (GWStack)
>
> - (void)push:(id)inObject
> {
> if(inObject) [self addObject:inObject];
> }
>
> - (id)pop
> {
> id theResult = nil;
> if([self count])
> {
> theResult = [[[self lastObject] retain] autorelease];
> [self removeLastObject];
> }
> return theResult;
> }
>
> @end
Thanks for the reply. I'm going to add this stuff as a category on the
NSMutableArray class.

Michael Ash writes:
> Lorenzo Thurman wrote:
>> Is there no stack class or equiv in Cocoa? Do I have to roll my own?
>> I'll probably just use an array, unless there are better suggestions.
>
> NSMutableArray will do the job just fine. Push is addObject:, pop is a
> lastObject followed by a removeLastObject. (Remember to either finish
> using the object or retain it before the remove.) There's no point in
> having a separate stack class when an existing one will do. You can do
> similar things to use them as a queue.

Or, if you're using C++ (or Objective-C++), you could use an appropriate
STL container template.

-- David

On 2007-06-02 12:21:43 -0700, shamino RemoveThis @techie.com (David C.) said:

> Michael Ash writes:
>> Lorenzo Thurman wrote:
>>> Is there no stack class or equiv in Cocoa? Do I have to roll my own?
>>> I'll probably just use an array, unless there are better suggestions.
>>
>> NSMutableArray will do the job just fine. Push is addObject:, pop is a
>> lastObject followed by a removeLastObject. (Remember to either finish
>> using the object or retain it before the remove.) There's no point in
>> having a separate stack class when an existing one will do. You can do
>> similar things to use them as a queue.
>
> Or, if you're using C++ (or Objective-C++), you could use an appropriate
> STL container template.

However, you'd still have to add the appropriate -retain/-release calls
for objects stored in the container. In which case, you're better off
just using NSMutableArray.


--
Clark S. Cox III