Re: I: TODO: Allow substring/replace() to get/set bit values

> As you say, there's really no point in changing the internal
> representation, and if you don't find replace() useful either, then
> why are you even working on this at all?

I would like a get_bit / set_bit for bit strings, as I find them useful.
get_bit could be a simple call to substring, but there's no way of doing a set_bit on a bit string as far as I know.

I don't like the "replace" syntax for bit strings since it won't give you the same functionality of set_bit,
plus I don't really see how someone would want to look for a bit string and replace it with another bit string.
But I see that someone might want to overlay a bit string with another (this is different from "replace" since you
have to tell the position where the replacing would start, instead of looking for a bit string).

To sum up:

1) a new function, "get_bit", that calls substring
2) a new function, "overlay", that replaces bits (starting at a certain position)
3) a new function, "set_bit", that calls overlay


> Since the latest discussion
> of this is more than five years old, it's unclear that anyone even
> cares any more.  It seems to me that making replace overlay a
> substring of bits could be a reasonable thing to do, but if nobody
> actually wants it, then the simplest thing to do is remove this from
> the TODO and call it good.

I understand: it would be both a useful feature to me and a way to start coding postgres.

But, of course, if there's no interest, I'll pass...