Feasibility of a Span class in java

[Red IO]

This looks like it has a pretty large overhead when accessing multiple
values. I think it would be more beneficial to have 1 object which
represents the whole range like a list. And is able to subdivide like a
memory segment. It would practically be a user friendly wrapper for memory
segments. The biggest challenge with an api like this is
1. Primitives inability to be efficiently generic and 2. Integration with
the whole jdk. The first could be solved in in 2 ways: Valhalla delivers
generics over primitives (still in development) or old school with a ton of
duplicate code.
The second problem would be a group effort. To effectively use this kind of
api it would need integration in strings, buffers, arrays, lists, streams
and everywhere you might find a continuous block of data. This would
require it to become an agreed goal to create it. Otherwise the effort
would be wasted.

On Mon, Nov 7, 2022, 18:34 Remi Forax <forax at univ-mlv.fr> wrote:

> It's on my TODO list :)
>
> You create an interface
>   interface MutableSpan {
>     int value();
>     void value(int value);
>   }
>
> and you can map it to any Panama memory because this is implemented as
> value class with two fields, a memory segment (or whatever the actual name)
> and an index.
> Then you need to see a contiguous space of memory as a List of span
> objects where the value class instances representing the value are created
> on the fly when asked.
>
> Rémi
>
> ------------------------------
>
> *From: *"Red IO" <redio.development at gmail.com>
> *To: *"panama-dev" <panama-dev at openjdk.org>
> *Sent: *Monday, November 7, 2022 5:59:28 PM
> *Subject: *Feasibility of a Span class in java
>
> Following the development and plans for both Panama's memory access api
> and the required changes provided by Valhalla while looking at c#'s
> directions for the last few years I was wondering if writing a class that
> serves as a universal and easy-to-use interface for accessing memory of all
> sorts of "value based" types inspired by c#' s Span struct would be
> beneficial for Java. Of course this assumes the completion of the memory
> api (panama) , the generic unification (Valhalla) and custom value based
> types (Valhalla). The idea is to speed up array and string manipulation by
> using short lived slicing objects (Span). I already wrote a poorly
> implemented slicer for strings and saw incredible performance gains in
> comon operations like substring and split.
>
>
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