simplify_categorical?

[edwindj]

rules <- validator( A %in% c("a1", "a2", "a3")
                  , if (A == "a1") x > 0
                  , if (A == "a2") x > 0
                  )

could be simplified into

rules <- validator( A %in% c("a1", "a2", "a3")
                  , if (A %in% c("a1", "a2")) x > 0
                  )