I see, thanks for the clarification. It does seem like you are purposefully creating a situation in which type will fail since something more likely: (type (proxy [clojure.lang.IRef][]))
works fine. I'm wondering if a CLOS-like system would really have to handle such a degenerate (in the technical sense :) case as the one you've pointed out? I'm interested in hearing reasons if there is one. David On Sun, Mar 29, 2009 at 5:22 PM, mikel <mev...@mac.com> wrote: > > > > On Mar 29, 1:34 am, David Nolen <dnolen.li...@gmail.com> wrote: > > On Sun, Mar 29, 2009 at 1:25 AM, mikel <mev...@mac.com> wrote: > > > > > (type (proxy [clojure.lang.IMeta clojure.lang.IRef][])) > > > > > java.lang.UnsupportedOperationException: meta (NO_SOURCE_FILE:0) > > > [Thrown class clojure.lang.Compiler$CompilerException] > > > > > No doubt someone is going to point out that the proxy object I created > > > there is useless; that's true, but beside the point. The point is that > > > it's straightforward to create some value v for which (type v) is > > > undefined. In order to make a Clojure-friendly version of CLOS, you > > > need some concept of object type such that you can define a function > > > that returns a sensible type for any value. > > > > Not totally following you here as: > > > > (proxy [clojure.lang.IMeta clojure.lang.IRef][]) > > > > immediately throws an error. I can't think of a situation in Clojure > where > > the type function does not return a usable value. Let me know if I'm > wrong, > > but your example is not a case as far as I can tell. > > If you type that expression at the REPL, it throws for the same reason > that calling type on it throws: because the print method for it calls > meta, which is not implemented. > > > --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
