Jon Pretty

Single letter type variables are mostly a bad idea, except when they have no semantic meaning. Monoid[A] is ok. StateChange[A, B] is not, I prefer StateChange[Before, After]. Now let's watch as my follower count suddenly starts dropping...

Either[L, R] is a good compromise.

So, I'm torn on this. I do exactly that most of the time, but that's out of guilt. I really want to write `Either[Left, Right]` but can't work up the courage to do so...

Maybe the reason you're torn is that "left" and "right" look like they have semantic significance, but it's just a decoy. There's almost certainly nothing sinister about anyone's choice for the first type parameter, and you could happily swap them.

That pun left me speechless