Thanks for the response - guess it is the best one can do living in this mixed mutable/immutable world.
Has the seq'ed version of the java byte array become immutable or do we have to pray that nobody changes the underlying array values? -FS. On Mar 24, 2010, at 12:40 PM, André Ferreira wrote: > 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. -- 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.
