Iterate over bit ranges #491
Description
Sometimes we want to find the ranges of 1 bits, and there's no obviously efficient way to do that currently.
(Maybe I'm missing something!).
If #22 was implemented, then we could do it without allocation, but currently
the only way I can think of doing it with reasonable efficiency (avoiding O(nbits)
complexity I think) is by using Flip and two iterators.
Providing a way to iterator over the unset bits or providing a way to iterate
over the bit-ranges would make this more efficient and/or convenient.
Something like this, perhaps:
// Ranges returns an iterator over all the [start, end)
// ranges of 1-bits in b.
func (b *Bitmap) Ranges() iter.Seq2[uint64, uint64]
Given that, it's trivial to write a function to iterate over the inverted bits.
PoC of the range functions using Flip: https://go.dev/play/p/Ss3T8NCDdJ0