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https://issues.apache.org/jira/browse/CRUNCH-650?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16083090#comment-16083090
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Josh Wills commented on CRUNCH-650:
-----------------------------------
Hey [~davw] is super-nice, thanks. My concern with shapeless has always been
the extra JAR dependency, esp. since folks use it so heavily downstream of the
project, and I wasn't sure how good the backwards compatibility story was there
(i.e., I would like to avoid another Guava nightmare.) What do you think?
> Support case classes and tuples without reflection or codegen using shapeless
> -----------------------------------------------------------------------------
>
> Key: CRUNCH-650
> URL: https://issues.apache.org/jira/browse/CRUNCH-650
> Project: Crunch
> Issue Type: Improvement
> Components: Scrunch
> Reporter: David Whiting
> Assignee: David Whiting
> Attachments:
> 0001-Replace-generated-tuple-code-and-reflective-case-cla.patch
>
>
> Scrunch support for case classes is pretty buggy, only supports a subset of
> scala versions, and fails at runtime instead of compile time if something
> goes wrong. Additionally, the support of tuple types via code generation is
> awkward and unnecessary.
> This patch should hopefully solve both of these with a shapeless
> (https://github.com/milessabin/shapeless) based solution which should be much
> simpler and more reliable, by defining a mechanism for deriving PTypeH
> instances for HLists where PTypeH instances for each type in the list is
> known.
> We have used it in a few production cases at SC for a while, and the unit and
> integration test suite passes, but I didn't write any new tests specifically
> for this purpose. Hopefully they should be covered by the existing tests
> using case classes and tuples.
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