Fix GetEnumerator

[philjdf]

Would close #242

[jgiannuzzi]

Given the ABI change in this PR, and given that 5.0.0-beta3 has now been out and stable for a while, I would like to release 5.0.0 first, and then release 6.0.0-beta1 immediately after with the upgrade to Arrow 6.0.0 and this PR.

@philjdf @adamreeve @adeboyed what are your thoughts on that?

[adeboyed]

Could this PR be included in the 5.0.0 release?

Upgrading to Arrow 6 may potentially lead to extended testing to ensure that the new features are supported and any API changes are made.

[jgiannuzzi]

Upgrading to Arrow 6 may potentially lead to extended testing to ensure that the new features are supported and any API changes are made.

If you are talking about ParquetSharp itself, then there are no API changes stemming from the upgrade to Arrow 6, and no new features. All the work has already been done in #230 and is just waiting for 5.0.0 stable to be released.
Let me know if you meant something else!

Could this PR be included in the 5.0.0 release?

If you mean 5.0.0 stable, then I would be quite reluctant in having an ABI change included without releasing another beta first. We could however include it in another 5.0.0 beta. This would push the work on the 6.0.0 series further however, which I'm not really keen on, especially as #68 and #229 would be fixed by it.

[jgiannuzzi]

@adeboyed could you please let me know today if my comment above makes sense to you — if yes, I'll go ahead and release 5.0.0 and 6.0.0-beta1 (@philjdf and @adamreeve already agreed offline with this approach)

[adeboyed]

Hi Jonathan, this approach makes sense to me.
As an aside, we should change the comment here:

ParquetSharp/README.md

Line 145 in 8ce5932

In the 5.0.X beta versions, reading nested structures was introduced. However, nesting information about nulls is lost when reading columns with Repetition Level optional inside structs with Repetition Level optional. ParquetSharp does not provide information about whether the column or the enclosing struct is null.

to reflect that this logic has made it into a release version.

[jgiannuzzi]

Good catch @adeboyed! I made that change in PR #246 and released 5.0.0 stable.

[jgiannuzzi]

The upgrade to Arrow 6.0.1 has also been merged (PR #247).

[jgiannuzzi]

ParquetSharp 6.0.1-beta1 has been released with this fix.