On Friday, 7 November 2014 at 14:11:32 UTC, bearophile wrote:
(This is a partial repost from a recent D.learn thread.)
In Phobos we have SortedRange and assumeSorted, but I do find
them not very good for a common enough use case.
The use case is to keep a sorted array, keep adding items to it
(adding larger and larger items at the end. Or sometimes even
inserting items in the middle. In both cases I keep the sorting
invariant). And while I add items, I also now and then want to
perform a binary search on the sorted range.
So sometimes I'd like to do something like this (but a
SortedRange doesn't have append):
struct Foo { int x; }
SortedRange!(Foo[], q{ a.x < b.x }) data;
data ~= Foo(5);
immutable n = data.upperBound(Foo(2)).length;
Bye,
bearophile
Facing this same problem, a while ago I started work on a
generic, higher-order container that provides insertion, deletion
and search while keeping itself sorted:
https://gist.github.com/JakobOvrum/f1738d31bb7ba7a46581
The above is just a WIP; it's not complete. Of course, positional
container primitives like `insertFront` and `insertBack` will not
be supported.
The implementation is fairly messy due to the lack of traits for
containers, as well as due to some deficiencies in `SortedRange`.
It's obviously useful for arrays, and it's kind of clever how it
can merge lists efficiently, but I'm not sure if it's really
worth all the effort; is it really useful to have something like
this that aims to support such a wide range of underlying
containers? Is it actually useful in real programs for anything
but arrays? So, I stopped working on it...
