2 Nov
2014
2 Nov
'14
9:01 a.m.
Chris, thank you for the links. I now understand ExceptT a lot better. Roman, thank you for the full program. What happened was I copy-pasted runExceptT $ ExceptT a <|> ExceptT b from your email into ghci. But you said the latest transformers was required, so I did the install. Finally, I saw an "A" printed out and went "Hey, that's not right!" Returning to the mail client, I referred back to Semen's original query and copy-pasted from there. But really it was A then B that I saw and not B then A. So mea culpa. Truth be told, all that while I was figuring out how to get Semen's "liftA2 (<|>)" to work and suffered cognitively from the lazy I/O solution I pursued. -- Kim-Ee