Era Scarecrow:
As you guess I have had to use many arrays of bits in my programs
:-)
4124 - Set/reset all bits ie:
BitArray ba = BitArray(100);
ba[] = true;
Others haven't been done yet.
Among those 4124 suggestions the most important, and very simple
to implement, are:
- set n-th bit (this can be a little more efficient than bs[n]=1;)
- reset n-th bit (this can be a little more efficient than
bs[n]=1;)
Another commonly needed operation is a very fast bit count. There
are very refined algorithms to do this.
7487 - Done. When prepending it extends the array to size_t
extra and slowly backtracks until it needs to do it again.
Leaving a bit of "capacity" at the beginning is a good idea.
7488 - Done, union used and is 'compact' version (by default or
resized and can fit)
Good, this makes BitArray usable in many other situations :-)
Related:
http://d.puremagic.com/issues/show_bug.cgi?id=6697
Not so sure. Could make a multi-dimentional one that returns
slices to various sections, but that's iffy. I'd need an
example of how you'd use it with BitArray before I could build
a solution.
I have needed many times a fast BitMatrix, but I see it as a data
structure distinct from BitArray, so don't worry about making
them inter-operate.
For me a BitMatrix must be as fast as possible, even if this
causes some waste of memory (see my implementation in the attach
of issue 6697) and I use it for medium and large bit matrices.
Generally I don't to count the set bits in a bit matrix. So the
two data structures need different capabilities and they are
better implemented in different ways (this means a FastBitMatrix
is not an array of a BitArray!).
Taking a row of a FastBitMatrix and turning it into a a BitArray
sounds cute, but generally I don't need to do this operation, so
I don't care about this feature.
Bye,
bearophile
