Req #60926 [Com]: LIFO/FIFO iterator modes for priority queues
Edit report at https://bugs.php.net/bug.php?id=60926&edit=1
ID: 60926
Comment by: franssen dot roland at gmail dot com
Reported by:franssen dot roland at gmail dot com
Summary:LIFO/FIFO iterator modes for priority queues
Status: Open
Type: Feature/Change Request
Package:SPL related
Operating System: Ubuntu
PHP Version:5.4.0RC6
Block user comment: N
Private report: N
New Comment:
Of course the idea initially was to avoid "arrays" here... not to end up using
both.
Think i'll have to bench;
* object using array only (data + priority + order); no use fancy PHP 5.3 stuff
;-)
* object using priority queue (data + priority) and array (order); not against
semantics (?)
* object extending priority queue and extra array internally (order); all logic
nicely encapsulated in compare() / against semantics (?)
Previous Comments:
[2012-01-30 18:23:22] franssen dot roland at gmail dot com
> "it really does not matter which one comes first"
So why cant we control it then? ;-)
However, you probably mean you shouldn't have to rely on it. Which makes sense.
Still.. i was so close with a out-of-the-box event listener data structure ^^ I
guess i'll compose the priority queue for internal usage and store the order of
shared priorities myself. It can be done.
[2012-01-30 03:09:10] carloschilazo at gmail dot com
I believe this goes against the definition of a priority queue, if you insert
them
with the same priority then it really does not matter which one comes first...
I understand what you are asking, but if you need them like that then you could
maybe use another data structure or a mixture, or user different priorities..
[2012-01-29 19:31:07] franssen dot roland at gmail dot com
Description:
PHP version is actually PHP5.4RC3
It would be nice to be able to maintain the input order in a SPL priority queue
when multiple values share the same priority.
E.g. FIFO and LIFO
The current "mode" is neither one of these. I guess this is best
peformance-wise but sometimes you want to be explicitly, for instance when
registering event listeners; you expect them to run in order.
Test script:
---
insert('a', 100);
$queue->insert('b', 100);
$queue->insert('c', 110);
$queue->insert('d', 90);
foreach($queue as $element) {
var_dump($element);
echo '';
}
echo '';
$queue2 = new \SplPriorityQueue;
$queue2->insert('a', 100);
$queue2->insert('b', 100);
foreach($queue2 as $element) {
var_dump($element);
echo '';
}
Expected result:
string(1) "c"
string(1) "a"
string(1) "b"
string(1) "d"
string(1) "a"
string(1) "b"
Actual result:
--
string(1) "c"
string(1) "b"
string(1) "a"
string(1) "d"
string(1) "a"
string(1) "b"
--
Edit this bug report at https://bugs.php.net/bug.php?id=60926&edit=1
Req #60926 [Com]: LIFO/FIFO iterator modes for priority queues
Edit report at https://bugs.php.net/bug.php?id=60926&edit=1
ID: 60926
Comment by: franssen dot roland at gmail dot com
Reported by:franssen dot roland at gmail dot com
Summary:LIFO/FIFO iterator modes for priority queues
Status: Open
Type: Feature/Change Request
Package:SPL related
Operating System: Ubuntu
PHP Version:5.4.0RC6
Block user comment: N
Private report: N
New Comment:
> "it really does not matter which one comes first"
So why cant we control it then? ;-)
However, you probably mean you shouldn't have to rely on it. Which makes sense.
Still.. i was so close with a out-of-the-box event listener data structure ^^ I
guess i'll compose the priority queue for internal usage and store the order of
shared priorities myself. It can be done.
Previous Comments:
[2012-01-30 03:09:10] carloschilazo at gmail dot com
I believe this goes against the definition of a priority queue, if you insert
them
with the same priority then it really does not matter which one comes first...
I understand what you are asking, but if you need them like that then you could
maybe use another data structure or a mixture, or user different priorities..
[2012-01-29 19:31:07] franssen dot roland at gmail dot com
Description:
PHP version is actually PHP5.4RC3
It would be nice to be able to maintain the input order in a SPL priority queue
when multiple values share the same priority.
E.g. FIFO and LIFO
The current "mode" is neither one of these. I guess this is best
peformance-wise but sometimes you want to be explicitly, for instance when
registering event listeners; you expect them to run in order.
Test script:
---
insert('a', 100);
$queue->insert('b', 100);
$queue->insert('c', 110);
$queue->insert('d', 90);
foreach($queue as $element) {
var_dump($element);
echo '';
}
echo '';
$queue2 = new \SplPriorityQueue;
$queue2->insert('a', 100);
$queue2->insert('b', 100);
foreach($queue2 as $element) {
var_dump($element);
echo '';
}
Expected result:
string(1) "c"
string(1) "a"
string(1) "b"
string(1) "d"
string(1) "a"
string(1) "b"
Actual result:
--
string(1) "c"
string(1) "b"
string(1) "a"
string(1) "d"
string(1) "a"
string(1) "b"
--
Edit this bug report at https://bugs.php.net/bug.php?id=60926&edit=1
Req #60926 [Com]: LIFO/FIFO iterator modes for priority queues
Edit report at https://bugs.php.net/bug.php?id=60926&edit=1
ID: 60926
Comment by: carloschilazo at gmail dot com
Reported by:franssen dot roland at gmail dot com
Summary:LIFO/FIFO iterator modes for priority queues
Status: Open
Type: Feature/Change Request
Package:SPL related
Operating System: Ubuntu
PHP Version:5.4.0RC6
Block user comment: N
Private report: N
New Comment:
I believe this goes against the definition of a priority queue, if you insert
them
with the same priority then it really does not matter which one comes first...
I understand what you are asking, but if you need them like that then you could
maybe use another data structure or a mixture, or user different priorities..
Previous Comments:
[2012-01-29 19:31:07] franssen dot roland at gmail dot com
Description:
PHP version is actually PHP5.4RC3
It would be nice to be able to maintain the input order in a SPL priority queue
when multiple values share the same priority.
E.g. FIFO and LIFO
The current "mode" is neither one of these. I guess this is best
peformance-wise but sometimes you want to be explicitly, for instance when
registering event listeners; you expect them to run in order.
Test script:
---
insert('a', 100);
$queue->insert('b', 100);
$queue->insert('c', 110);
$queue->insert('d', 90);
foreach($queue as $element) {
var_dump($element);
echo '';
}
echo '';
$queue2 = new \SplPriorityQueue;
$queue2->insert('a', 100);
$queue2->insert('b', 100);
foreach($queue2 as $element) {
var_dump($element);
echo '';
}
Expected result:
string(1) "c"
string(1) "a"
string(1) "b"
string(1) "d"
string(1) "a"
string(1) "b"
Actual result:
--
string(1) "c"
string(1) "b"
string(1) "a"
string(1) "d"
string(1) "a"
string(1) "b"
--
Edit this bug report at https://bugs.php.net/bug.php?id=60926&edit=1
