Feature #21821: Add Stack and SizedStack classes

• Status: Open
• Assignee: -
• Target version: 4.1

[byroot (Jean Boussier)]

Context

Queue and SizedQueue are very useful and performant constructs, however they only allow for FIFO queues.
Some use cases do call for LIFO queues AKA stacks.

For instance, in the case of connection pool, it's often preferable to use a stack.

Feature

I'd like to introduce Stack and SizedStack classes, to mirror Queue and SizedQueue.
They'd have exactly the same method and behavior at the exception of dequeuing order.

Thread namespace?

Currently Queue and SizedQueue are technically defined under Thread and aliased in Object.
I wonder if that's something we should do for Stack too, or just some historical thing we shouldn't perpetuate.

[byroot (Jean Boussier)]

• Related to Feature #21721: Allow `Queue` and `SizedQueue` to be used as LIFO queues added

[nobu (Nobuyoshi Nakada)]

byroot (Jean Boussier) wrote:

Currently Queue and SizedQueue are technically defined under Thread and aliased in Object.
I wonder if that's something we should do for Stack too, or just some historical thing we shouldn't perpetuate.

I think it will depend on what you achieve with Stack.
If you want to use it for inter thread communication, Thread namespace should be suitable.
Otherwise, if you want just simple push/pop operations, why isn't Array enough?

[byroot (Jean Boussier)]

I think it will depend on what you achieve with Stack.

Yes, the point is to use it in cases where synchronization is needed, hence Array is not suitable. Typically connection pools: https://github.com/mperham/connection_pool/blob/8ba2715edca69d6162fd4f798997b74dd64e9529/lib/connection_pool/timed_stack.rb