On Tuesday, March 31, 2015 at 7:49:52 AM UTC-4, Jeroen van Dijk wrote: > > Thanks for sharing James! I'll have a look. > > As a side note, I see in the example code that you are dissoc-ing on the > component. This can lead to unexpected behaviour as I have > experienced (mostly in repl cases), as this will return a map instead of a > record when the field is not part of the record. This is also mentioned in > the readme of https://github.com/stuartsierra/component where `(assoc > component ::field nil)` is recommended >
Perhaps there should be an enablable warning for that, the way there already is for reflection. When enabled, it would go off if a) Code was compiled for (dissoc x :foo) where x could be determined by static analysis to be an instance of a record type for which :foo is a base field, and also if b) A dissoc on a record returned a plain map, or at least b). Enabling the warning could work partly by actually redefining clojure.core/dissoc, as with disabling it, so that the overhead of the warning code was completely avoided with it disabled. With it enabled, the code path in dissoc that produces a non-record from a record would also emit a message to stderr with general wording such as "warning: dissocing base field :foo from MyRecord, producing hash map, at line 666 of evil.clj". (The line and file being obtained by constructing a Throwable and then dismantling and examining its StackTraceElements.) Turning this on and exercising a project (especially, running all the tests if it has good test coverage) would then find most potential-bugs of this sort. -- 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.
