My understanding is that old (previously constructed) instances of a record follow the old implementation. To get the new behavior after recompiling a record you must construct a new instance.
On Aug 26, 10:51 am, Armando Blancas <armando_blan...@yahoo.com> wrote: > I ran your sequence without redefining Foo and got 20 instead of 1/5. > I don't know how that redefinition affects the evaluation of bar. > > Clojure 1.2.0 > user=> (defprotocol Foo (bar [this x])) > Foo > user=> (defrecord fooed [] Foo (bar [this x] (* 2 x))) > user.fooed > user=> (extend-type Object Foo (bar [this x] (/ 2 x))) > nil > user=> (def fooey (fooed.)) > #'user/fooey > user=> (bar fooey 10) > 20 > > On Aug 25, 8:55 am, DeverLite <derby.lit...@gmail.com> wrote: > > > > > So if I do this in a clean REPL > > > Clojure 1.2.0 > > user=> (defprotocol Foo (bar [this x])) > > Foo > > user=> (defrecord fooed [] Foo (bar [this x] (* 2 x))) > > user.fooed > > user=> (defprotocol Foo (bar [this x])) > > Foo > > user=> (extend-type Object Foo (bar [this x] (/ 2 x))) > > nil > > user=> (def fooey (fooed.)) > > #'user/fooey > > user=> (bar fooey 10) > > 1/5 > > user=> (defrecord fooed [] Foo (bar [this x] (* 2 x))) > > user.fooed > > user=> (def fooey (fooed.)) > > #'user/fooey > > user=> (bar fooey 10) > > 20 > > > I would have expected 20 the first call to bar to be 20. > > > This is a natural sequence of lines to execute if you---for > > instance--- have Foo defined in file A and fooed in file B, and you > > then add a default implementation using extend-type in file A and then > > recompile file A. > > > This scenario is easily fixed by recompiling file B (as the last few > > lines demonstrate). > > > I don't see any easy way to actually fix this behavior (though my > > understanding of how protocols are implemented is largely based on > > seeing how they behave and my limited knowledge of the JVM, rather > > than actually looking at the code), but it does seem like it would be > > less surprising if it could be accomplished. > > > Thoughts? Should I post this as a ticket in assembla? -- 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
