remove Control.Applicative warning

[MetaMemoryT]

since we depend on base >= 4.6 not going to support older versions
anyways.

[meteficha]

I'm not sure what you mean but current esqueleto depends on base >= 4.5. Besides, base-4.6's Prelude doesn't export <$> AFAICS.

[MetaMemoryT]

Oops I missed that. Guess I would need cpp to remove warning and be cross compatible.

[meteficha]

AFAIU, <$> is exported by prelude only on base-4.8 (GHC 7.10).

[MetaMemoryT]

Aha, I found a better solution than cpp.

Would you accept a PR that used base-compat? I would use the technique described here haskell-compat/base-compat#22 to solve Control.Applicative warnings.

[meteficha]

I'm not sure. It's just a warning on the test suite, so adding a dependency seems a bit too heavy handed. Also, it doesn't look like any package related to esqueleto in some way uses it.

[snoyberg]

I agree with @meteficha here.