On Wed, 27 Jun 2012 13:44:34 -0400, Jonathan M Davis <jmdavisp...@gmx.com>
wrote:
On Wednesday, June 27, 2012 08:25:04 Steven Schveighoffer wrote:
On Wed, 27 Jun 2012 05:37:00 -0400, Minas Mina
<minas_mina1...@hotmail.co.uk> wrote:
> How can I do that?
>
> Why not list.remove(x); like in STL?
SList is quite unusable.
If you are looking for STL-like containers, there is dcollections which
has a doubly-linked list, and supports syntax like you want.
http://www.dsource.org/projects/dcollections
There concept of SList is unusable IMHO. The singly-linked list is one
of the
most useless data structures ever invented. It does have some use cases,
but
almost always what you really want is doubly-linked list.
The thing that makes SList useless is the O(n) removal. Nobody will ever
use SList when they can write a replacement that has O(1) removal in 10
minutes.
The concept of singly-linked lists is most certainly not useless. They
are perfect for FIFO queues, or LIFO stacks, and they consume 1/3 less
space than a doubly-linked list (at least for an int/size_t)
My somewhat loose belief is that making a generic singly-linked list is a
waste of time -- it's too difficult to implement in a way that is
optimized for the intended use.
As for std.container, the basics of std.container are good, but the
documentation isn't good enough for some basic stuff, and some of it
needs to
be ironed out a bit. For instance, the basic idea of how remove works is
fine
given how ranges work (though it's arguably one of those few places where
ranges are worse than iterators - hence why dcollections has cursors),
and
it's exactly what you want in the general case, but it's arguably overly
complicated for a lot of basic use cases. Adding stuff like removeFirst
which
removed the first value which matched would greatly simplify a number of
basic
use cases.
I haven't used std.container all that much, but I find the terminology
very obtuse and verbose. I can't imagine every using for example
upperBound without having to look up what it does.
I understand the point, but it needs shortcuts. Like how you can type
writeln("x") instead of stdout.writeln("x"). I think that's a small
difference that is a huge win.
But regardless, any API improvements pale in comparison to the O(n)
removal problem for SList.
I've been meaning to figure out a small set of basic functions like that
which
would improve the API's usability for many common cases and propose
them, but
there hasn't been much point in trying to do anything with it, since
that sort
of thing needs to get passed Andrei (who is likely to say that the
current
solution with find and take is just fine, since it's nicely generic and
covers
all use cases), but he's been busy.
It doesn't hurt to propose... Personally, I don't see myself ever using
std.container when I prefer the API of dcollections. But that obviously
isn't going to be the popular choice, since it's not in phobos.
-Steve
