[chuck-users] push but no pop?
mike clemow
gelfmuse at gmail.com
Mon Apr 13 21:33:17 EDT 2009
Rob, Kas,
+1 on the popBack() feature request. But I would also like to add
some syntactic icing to the cake in the form of an inverse append
operator:
If this means "push":
myArray << 5;
then this should mean "popBack":
myArray >> int myInt;
after which:
<<< myInt >>>;
should print "5 (int)"
Consistency is king.
_mike
2009/4/12 Kassen <signal.automatique at gmail.com>:
> Rob;
>
>> FEATURE REQUEST
>>
>> As written, array's popBack() function has a void return. It would be
>> nice if popBack() returned the element it removed, so we could write the
>> code like this:
>
> I agree with this, it's not clear to me why it doesn't do this already.
> Actually I thought it did but only worked correctly for primitives. I just
> tested and that turns out to be a mistake.
>
> I think it's clear that we need this and I hope it'll be addressed one when
> somebody goes over the series of bugs related to arrays and type; it can't
> be very hard, assuming the other existing issues will be addressed. Our
> arrays need some loving care.
>
>
>>
>> BUG REPORT
>>
>> This may be operator error rather than a bug, but the following code:
>>
>> fun Element allocateElement() {
>> if ((_pool.size() => int size) > 0) {
>> _pool[size-1] @=> Element @ element;
>> size-1 => _pool.size;
>> return element;
>> }
>> return new Element;
>> }
>>
>> reports:
>>
>> chuck(20184,0xa018a830) malloc: *** error for object 0x5eb6e0:
>> double free
>> *** set a breakpoint in malloc_error_break to debug
>>
>> I think the problem may be in "return new Element" -- it may be trying to
>> return the Element itself, rather than a reference to the Element. If
>> that's the case, though, it seems like something that should be caught at
>> compile time.
>
> I suspect this is another case of the bits of the GC that are are already in
> there and occasionally collect things before they need to be collected.
> Until there is a new version I'm inclined to categorise anything related to
> more advanced operations on arrays involving no-primitive types on the
> "Clemow's bane" pile. First of all there is the issue that I think we are
> seeing here which involves the over-collection of things that aren't (yet)
> garbage, secondly there is the issue that if you do manage to get a item out
> of a array in a way like this ChucK will somehow lose track of what type it
> is at which point there will be issues of a extremely headache-inducing
> nature.
>
> Mike may be able to help you; I seem to remember him&me got something quite
> similar to this to work for some of his code but I forgot the details. The
> one thing my memory hasn't repressed is that the solution involved
> sprinkling the code with magical "@" signs, more or less at random :¬). I
> love ChucK but here be dragons.
>
> Yours,
> Kas.
>
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>
--
http://michaelclemow.com
http://semiotech.org
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