Teach genericAuto about new-style union construction. #927
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| (name', e, _) <- extractUnionConstructor u | ||
| if | ||
| | name == name' -> fmap (R1 . M1) (extractR e) | ||
| | otherwise -> fmap L1 (extractL u) |
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This instance's implementation is actually not covered by the new tests - GHC seems to prefer to recurse to the right and hence the following instance gets used, not this one, though I didn't try very hard to convince it not to.
The underlying bug is very similar to dhall-lang#915, and in fact this builds on the fix for that in dhall-lang#918. Closes dhall-lang#926.
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Thanks! |
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You're welcome! 🙂 |
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I discovered it wasn't working right in #926. The underlying bug is
very similar to #915, and in fact this builds on the fix for that in #918.
It looks like the single-constructor case is a different underlying
bug that I don't understand just yet, so let's tackle that separately.