Arrays are mutable, seqs immutable. Clojure ='s compares immutable structures by value, and mutable structures by reference (for the objects that it is aware of, for others it just prays that they have a resoanable equals method). This behaviour is described in the very interisting Henry Baker's egal Paper, and yields the cleanest equality semantics that I know of.
On 23 mar, 14:24, Frank Siebenlist <frank.siebenl...@gmail.com> wrote: > My REPL shows: > ... > user> (= (bytes (.getBytes "a"))(bytes (.getBytes "a"))) > false > user> (= (seq (bytes (.getBytes "a"))) (seq (bytes (.getBytes "a")))) > true > ... > > in other words, "equality" for java byte arrays is defined differently than > their seq'ed version. > > It seems that the native arrays are compared on their reference while the > seq'ed version on their value (as it should...). > > Sometimes the seq'ing seems implied, however, like in: > > ... > user> (first (bytes (.getBytes "a"))) > 97 > ... > > but for the "=" function it is not. > > This doesn't feel right and is confusing to say the least. > > Could anyone shed some light on this behaviour? > > Thanks, Frank. -- 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 To unsubscribe from this group, send email to clojure+unsubscribegooglegroups.com or reply to this email with the words "REMOVE ME" as the subject.
