3 ms·
I think the obvious implementation is `maybe (Left False) (maybe (Left True) Right)` If we have a value then we clearly have both layers. If we don't have a v
by dllthomas 8y ago
I think the obvious implementation is `maybe (Left False) (maybe (Left True) Right)`
If we have a value then we clearly have both layers. If we don't have a value then we need to distinguish Nothing from Just Nothing by way of the book.