Quite a frequent occurrence, welcome to the club! One simple check that the Clojure compiler could make is to produce a warning if any lazy result is discarded. I think that would catch 90% of the problems and give the user an immediate clue what to investigate. Well it sounds simple, but I have no idea where to start implementing it.
To me the big win of laziness is dealing with large collections, which would otherwise break. Regards, Tim. On Mar 2, 4:06 pm, max3000 <maxime.lar...@gmail.com> wrote: > Hi, > > I find the laziness in clojure very hard to wrap my head around. I > understand the idea and it's probably nice in theory. However, in real > life it doesn't seem really useful beyond hardcore mathematical > problems. > > Case in point, I just spent 2 hours debugging a piece of code (shown > below) that seemed simple enough. This is the 3rd time this week that > I've lost substantial time to laziness. I'm pretty pissed to tell the > truth and I find myself wrapping things in doseq more and more just to > be sure. I rarely use 'for' anymore, what's the point? > > Here is the code that gave me trouble: > > (map #(add-watch % watcher callback-fn) all-agents) > > This was not executing. I had to change it to the below expression: > > (doseq [agent all-labor-agents] > (add-watch agent total-labor-agent callback-fn)) > > This second expression seems less elegant than the map above. Why > doesn't clojure realize that an add-watch really should actually loop > over all-agents? Why is it that Java calls are not made in similar > expressions? > > Is laziness so useful that we should waste time investigating and > fixing errors like this? Sure, there could be special constructs for > laziness when we really need it. However, clojure shouldn't default to > it IMO. At this point, laziness is a nice concept but it feels > somewhat removed from reality to tell the truth. Of course I want to > iterate over my collection when I'm doing an add-watch! > > What am I missing? > > Thanks, > > Max --~--~---------~--~----~------------~-------~--~----~ 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 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 -~----------~----~----~----~------~----~------~--~---
