Data.Functor.Functor lacks the (<$) method
The export of Functor
from Data.Functor
comprises only the fmap
method, but not (<$)
. This is confusing, as the Prelude
exports Functor
fully, i.e. including (<$)
.
This issue is exacerbated by the fact that the export from Data.Functor
is the "canonical" definition in the sense that if you click on a link to Functor
in the haddocks, you're directed to the definition in Data.Functor
.
The origin of this issues lies in c3b8a749 ("Make Data.Functor compatible with non-GHC compilers"). I suspect that these compatibility concerns are less important today.