Still a newbie here, about to release my first Clojure project. But that clojure blob will take some digging on my part. I use a gummed up dereference function that checks for Throwable in the meantime.
My goal right now is to become a Dtomic freelancer. So much to learn! Which is why I'm doing projects. Only way I know to become proficient! So yeah, I need to get to the point where I can roll my own. Similarly, my first project builds on the send method, but I really need to get to the point where I can roll my own agent. In any case, thanks Francis. I can only promise more dumb questions in the future. ;-) On Friday, August 7, 2015 at 5:24:24 PM UTC-4, Francis Avila wrote: > > Huh, I was sure I had done this before, but I misremembered, I was using > my own promise that rethrew Throwable instances on deref (and it was in > clojurescript!) > > Clojure promises have no notion of failure, only realized/not-realized. > You need to deliver a sentinel type or value and check for it on deref, or > implement your own promise type which does it for you. (It's not that hard: > https://github.com/clojure/clojure/blob/clojure-1.7.0/src/clj/clojure/core.clj#L6803 > > ) > > On Friday, August 7, 2015 at 4:09:39 PM UTC-5, William la Forge wrote: >> >> Sorry, I meant to ask how to fail with a promise? It seems that there is >> no fail method. >> >> On Friday, August 7, 2015 at 4:52:47 PM UTC-4, Francis Avila wrote: >>> >>> Futures automatically capture exceptions raised in their bodies and >>> reraise them when the future is derefed. Promises also throw exceptions >>> when derefed. >>> >>> Unlike promises, futures are created with the code that delivers their >>> value, so calling fail and deliver explicitly on a future makes no sense. >>> >>> Think of futures as a thin wrapper around a promise which spawns a >>> thread, runs the code, and to the wrapped promise either delivers the >>> result of the code or calls (fail private-promise raised-exception) for you. >>> >>> On Friday, August 7, 2015 at 2:14:30 PM UTC-5, William la Forge wrote: >>>> >>>> A future fails when it throws an exception. How to do that with a >>>> future? >>>> >>>> It looks like (fail future exception) does not do the trick: >>>> http://dev.clojure.org/display/design/Promises >>>> >>>> -- You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en --- You received this message because you are subscribed to the Google Groups "Clojure" group. To unsubscribe from this group and stop receiving emails from it, send an email to clojure+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
