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https://issues.apache.org/jira/browse/ARROW-6386?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16926715#comment-16926715
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Wes McKinney commented on ARROW-6386:
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Do you want to document this as a comment in the C++ kernels code? I don't
think any changes need to be made to the columnar format documentation
> [C++][Documentation] Explicit documentation of null slot interpretation
> -----------------------------------------------------------------------
>
> Key: ARROW-6386
> URL: https://issues.apache.org/jira/browse/ARROW-6386
> Project: Apache Arrow
> Issue Type: Improvement
> Components: C++, Documentation
> Reporter: Benjamin Kietzman
> Assignee: Benjamin Kietzman
> Priority: Major
> Labels: pull-request-available
> Time Spent: 50m
> Remaining Estimate: 0h
>
> To my knowledge, there isn't explicit documentation on how null slots in an
> array should be interpreted. SQL uses Kleene logic, wherein a null is
> explicitly an unknown rather than a special value. This yields for example
> `(null AND false) -> false`, since `(x AND false) -> false` for all possible
> values of x. This is also the behavior of Gandiva's boolean expressions.
> By contrast the boolean kernels implement something closer to the behavior of
> NaN: `(null AND false) -> null`. I think this is simply an error in the
> boolean kernels but in any case I think explicit documentation should be
> added to prevent future confusion.
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