Hi,
Am Donnerstag, den 09.03.2017, 15:21 + schrieb Simon Peyton Jones
via ghc-devs:
> > +-- The "mapFB" rule optimises compositions of map and
> > +-- the "mapFB/id" rule get rids of 'map id' calls.
> > +-- (Any similarity to the Functor laws for [] is expected.)
>
> Yes, obviously. But
| +-- The "mapFB" rule optimises compositions of map and
| +-- the "mapFB/id" rule get rids of 'map id' calls.
| +-- (Any similarity to the Functor laws for [] is expected.)
Yes, obviously. But did you have a use-case, or did you just to this on
principle? If you don't have this rule what
