As for the reason.

Technically List was an immutable data-structure. Even if that is half-true. No special code was written that permits mutating a List. Still the List was written as the concept of being a Linked-List. so it provided O(1) append and O(1) removal at head, like imuutable List offers.

That you still theoretically could iterate to some element and change it, was accepted, and if somebody does that, it was his/her problem doing that stuff. List itself is still immutable as every operation created/returned a new List. Some operation on a List can be very efficent, some others not.

But overall, there is not much benefit of just using Array. The Array module also offers the same, currently even more, operations on Array that are also immutable in the sense that they always return a new Array. But Array is faster to create, faster to iterate and uses a lot less memory.

Even if not Benchmarked by me, i can assume that using an Array is probably always faster, maybe multiple times faster, than the same List operation. So there is no real point in ever using List.

Maybe i should write about that somewhere, but "immutable-programming" doesn't mean you must use persistent data-structures. While persistent data-structures can be useful, especially with tree data-structures, this is not much the case for a linked-list.

Otherwise when you restrict yourself to not change input values on a function, and always return new data, you basically do "immutable programming" even if nothing prohibits you from ever changing something. In Perl/Sq this approach should be used to get best performance.

I am still concerned about performance, not just being the best/complient solution to any paradigm, and we anyway have a lot of slow modules out there, especially OO Modules.

Update List #1

Description

Metadata

Metadata

Assignees

Labels

Projects

Milestone

Relationships

Development

Issue actions