On Mon, Apr 14, 2014 at 1:03 PM, Dimitri DeFigueiredo <defigueiredo@ucdavis.edu> wrote:

oldbuysell :: String -- "buy", "sell" or ""

Why is this String when you've defined the perfectly cromulent BuyOrSell datatype?

How can you be sure there won't be some accidental buggy code that sets the field to "buyy"?

-- Kim-Ee