scalaz/scalaz — comment on commit 0caa90387f722cf827f78430235236da12e3eab8
File: core/src/main/scala/scalaz/MonadTrans.scala line 4
By rwallace:

Nope, I had it as `Functor` originally but I wasn't confident enough to say that there wouldn't be instances that needed it to be a `Monad` as opposed to `Functor`.