+1 or -1 for renaming

Either.cond

to

Either.invariant

and making the left side the error one?

+1 for making left side as error one But I am curious about if that rename would be good for people entering FP world. With

cond

or maybe

conditionally

, probably every programmer all around the world will know what it means -> there some condition and some reaction to the condition’s result. With

invariant

-> I think this is a terminology with overhead and many people must learn by heart to know what it is doing