Yes, I understand the behavior perfectly well. The primitive int gets converted to a Long immediately, as this code demonstrates:
user=> (class (Integer/parseInt "5")) java.lang.Long The int isn't being "boxed" into a Long -- the type is being changed. I'm aware that I can "fix" things by converting the type back to an Integer manually, but that's not the point. Changing the types is unusual behavior that leads to hard to track down bugs like I ran into with the ClassCastException. My proposal still stands. -Nathan On Oct 19, 5:29 pm, Kevin Downey <redc...@gmail.com> wrote: > On Wed, Oct 19, 2011 at 5:14 PM, nathanmarz <nathan.m...@gmail.com> wrote: > > Here's a code example illustrating the problem I'm having: > >https://gist.github.com/1300034I've simplified it to the bare minimum > > necessary to illustrate the problem. > > > Agree 100% that ints and longs are broken in Java. The hashcode/ > > equality stuff is messed up. Clojure can try really hard to hide this, > > but it can't hide it completely since Java libraries can always return > > you Integer objects. The additional complexity added from changing the > > Existing Integer objects are unchanged. If the method call in your > example did return an Integer object then you would never notice > anything. > > > types on you isn't worth it IMO. > > > Here's my proposal for what I think would be better behavior: > > > 1. Clojure boxes ints into Integers rather than convert them into > > longs > > clojure does not convert ints into longs, you are putting a primitive > into a collection, which requires boxing, clojure 1.3 boxes ints as > Longs. If you put (Integer. …) around your call you will be fine. > > > > > > > > > > > 2. If you wrap the form in "(long ...)", Clojure skips the boxing and > > does what it does now. Since this is done explicitly, there's no > > confusion about types. > > > -Nathan > > > On Oct 19, 7:38 am, Stuart Halloway <stuart.hallo...@gmail.com> wrote: > >> > Thanks. I read through that and it didn't quite answer my question. To > >> > me it seems more logical that: > > >> > 1. Clojure defaults to longs when you create a new number (with a > >> > literal 0, 1, etc) > >> > 2. You can create ints by doing (int 0) > >> > 3. Clojure never changes the types of things you're using > > >> > I find Clojure's behavior of changing the types of primitive ints to > >> > longs highly unusual, and it is causing a lot of pain in upgrading > >> > Storm to 1.3. > > >> Integers and longs are going to be painful no matter what because they are > >> broken in Java, e.g. > > >> Object[] objects = new Object[] {-1, -1L}; > >> System.out.println(objects[0].hashCode()); > >> System.out.println(objects[1].hashCode()); > > >> Clojure avoids this pit by standardizing on longs, which leaves you with > >> the need to specifically request ints when you need them for interop. You > >> can use (int n) hints to select the correct interop method invocation, or > >> box an int if you want to hold on to a value guaranteed to be int. > > >> Can you post a code example that shows a problem you are having? > > >> Stu > > >> Stuart Halloway > >> Clojure/corehttp://clojure.com > > > -- > > 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 > > -- > And what is good, Phaedrus, > And what is not good— > Need we ask anyone to tell us these things? -- 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
