Just as a counter-anecdote, I have worked on large Clojure codebases (both ones I developed and ones I was unfamiliar with), including ones that interfaced with existing Java codebases, and have not experienced this problem to the degree you describe Colin. So while I believe these problems exist, I don't think it's a foregone conclusion that they must.
FYI, I've found that when working with a partially instrumented spec'ed clojure.core, that unexpected nil colls (and colls containing nil) are reported earlier and better (because they occur at the point they are introduced rather than later and several layers down in some RT method). On Friday, October 21, 2016 at 10:15:23 AM UTC-5, Colin Fleming wrote: > > This is a discussion that I've had a couple of times. I don't think that > interop is the main factor here, I think it's more that I'm programming > against a large codebase I don't understand well (I can't since it's around > 4 million LOC). I suspect that if I were programming against a large > undocumented Clojure codebase I'd have similar problems, or worse. > > Note that Java interop often gets the blame here, but it's worth pointing > out that in Clojure everything is Java interop in the end. (+ 1 x) or > (str/trim x) will give you an NPE as easily as in Java if you pass nil in > x. And even if Java interop *is* the root cause of the problem, > supposedly interop is idiomatic in Clojure, and interfacing with existing > Java systems is a key use case for continuing Clojure adoption. I don't > think that the type of application that Cursive is is as much of an outlier > as people think - anyone integrating with an existing system will probably > face similar problems. Indeed, after my previous conversations, several > people contacted me to say that their experience matched mine in similar > systems. > > People have also asked me about whether nil punning helps. In my > experience, it allows for some elegant code but it has a really terrible > tendency to mask bugs and push them much further into the system than would > otherwise be the case. It would be nice to be able to say that I'm > expecting a collection to be non-nil, and to get an NPE at the point of the > collection call if it's nil due to a bug, rather than just silently > returning nil and continuing. > > Also, when tracking down an NPE from a bug report, if there are collection > methods in the stack trace I now have to consider (at least) 3 cases: the > collection is unexpectedly nil, the collection is unexpectedly empty, or > the collection unexpectedly contains a nil value. This greatly increases > the space of problems that I have to consider as possibilities when trying > to work out what's going on. > > > > On 21 October 2016 at 05:39, Daniel <doubleagen...@gmail.com> wrote: > >> Just curious... What do you think the primary contributing factor is for >> Cursive's NPEs? Java interop? >> >> -- >> 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. >> > > -- 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.
