Make createCheckpointAndClose part of public interface #142
Conversation
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I suspect the CI failure on AppVeyor to be spurious; it looks like some kind of timeout setting up GHC 8.2. |
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It looks like the subType stuff was added in this commit, But no explanation anywhere of why or what the intended use case is. If I had to guess, the idea was to allow various backends to store other information in the |
Yes, I think that's the idea. Certainly that is how the Local backend uses it prior to this PR. It seems I dislike this design as a mechanism for extension, because it means there is no static type distinction between But the question remains as to whether we should keep this for backwards compatibility anyway. |
Fixes #112. This exposes
createCheckpointAndCloseviaData.Acid[.Abstract]and makes it work for all backends:createCheckpointAndCloseon these backends would throw an error as the downcast failed.)I've also removed the dynamically-typed stuff in a separate commit, since it is not used for anything else in
acid-state. It is conceivable that it might be used by dependent packages, though, so we could imagine keeping this in. I'm not convinced it provides a good interface though.This needs a changelog update, assuming there is consensus that this is a sensible change.