Hey Yotam,
Pattern matching clauses evaluate from left to right. You can get the
behavour you're after by swapping the arguments in the tuple:
case (stop, infi) of
(Just _, Nothing) -> 1
(_, _) -> 2
Evaluates to 2
On Tue, 20 Jun. 2017, 7:29 pm Yotam Ohad,
Hi, After reading "Push-Pull Functional Reactive Programming https://pdfs.semanticscholar.org/fb7a/879d639641341e025197b40afad9e21f0ce5.p..." I had an idea about deciding which, of two events, comes first. Instead of using forkIO, I tried something like the following:
infi :: Maybe Int infi = infi
stop :: Maybe Int stop = Nothing
test :: Int test = case (infi, stop) of (Nothing, Just _) -> 1 (_, _) -> 2
Here, infi is an action that never ends, and stop a function that ends immediately. I thought that the compiler would see that stop evaluates immediately to Nothing and thus will return 2, but it tries to evaluate infi and get stuck.
I think it happens because I am using a tuple to hold both values (but not really sure about it). Do you know a way to make this arrangement work?
Yotam _______________________________________________ Haskell-Cafe mailing list To (un)subscribe, modify options or view archives go to: http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-cafe Only members subscribed via the mailman list are allowed to post.