Replace each_allocated_chunk function with iter_allocated_chunks function

[TethysSvensson]

This implements the suggestion in #27.

[TethysSvensson]

Note that this currently removes the function each_allocated_chunk, since I believe this new functionality to be strictly superior. The iterator API is more usable, while also being safe to use as long as you do not look at any of the byte values. The type signature makes it clear exactly which parts are unsafe.

I can easily re-implement the old function on top of the iterator for backwards-compatiblity, if you prefer. If you want me to do this, I think we should consider marking as deprecated, or perhaps changed to use [MaybeUninit<u8>] slices instead of [u8] slices (though that you also be a breaking change).

[TethysSvensson]

By using google and github search, I have not been able to find any references to each_allocated_chunk outside of this crate or rustdocs. There might be users of the function in private or non-indexed code though.

[fitzgen]

By using google and github search, I have not been able to find any references to each_allocated_chunk outside of this crate or rustdocs. There might be users of the function in private or non-indexed code though.

I use it here, fwiw: https://github.com/fitzgen/dodrio/blob/22faf1eb60f9bcb16094e1b2f4575edfb203338e/src/change_list/emitter.rs#L43

[fitzgen]

Looks great, thanks @TethysSvensson!

Can you also reimplement each_allocated_chunk in terms of iter_allocated_chunks with a #[deprecated(note = "deprecated in favor of iter_allocated_chunks")] note?

Thanks!

[TethysSvensson]

By using google and github search, I have not been able to find any references to each_allocated_chunk outside of this crate or rustdocs. There might be users of the function in private or non-indexed code though.

I use it here, fwiw: https://github.com/fitzgen/dodrio/blob/22faf1eb60f9bcb16094e1b2f4575edfb203338e/src/change_list/emitter.rs#L43

That also shows up on github search now, but didn't before. It still does not show up on google search. This makes me a lot less inclined to trust github search in the future.

Can you also reimplement each_allocated_chunk in terms of iter_allocated_chunks with a #[deprecated(note = "deprecated in favor of iter_allocated_chunks")] note?

Done.

[fitzgen]

Thanks so much!

[fitzgen]

That also shows up on github search now, but didn't before. It still does not show up on google search. This makes me a lot less inclined to trust github search in the future.

FWIW, I think github will only show the first two hits in a file, so if there are multiple occurrences, they might be hidden. In the specific dodrio example, the first two occurrences are inside comments, so the actual call is hidden :-/