I have been using Clojure for just under a week, but ... I have been using CL for almost three years now and have lately been looking at and actually using Clojure. I think that it should be easy to write correct code then put it a bit of work later to make it fast.
On Jun 18, 12:44 pm, Christophe Grand <christo...@cgrand.net> wrote: > On Fri, Jun 18, 2010 at 8:58 AM, Richard Newman <holyg...@gmail.com> wrote: > > It only takes one library to screw up, and the whole stack falls down. > > Screwing up can occur because of omission (fact being written with a "1", > > not "1N", and not being tested with large inputs), or by design. > > It can already happen: a library can screw you by design. > > (defn fact [n] (loop [r (int 1) n (int n)] (recur (* r n) (dec n)))) > user=> (fact 40) > java.lang.ArithmeticException: integer overflow (NO_SOURCE_FILE:0) > > Actually people who want numerical perfs have to do very invasive type > hinting and other interfaces workaround because primitives are... > primitives (not objects). > > With contagious bigints (let's nick name them "safeints" and assume > they are not BigInteger but something à la kawa) a single N on > literals or having all your inputs going through a safeint conversion > would trigger safe computations (unless you try to call a static > primitive-hinted fn but the compiler would then bark). > > Of course a rogue fn can still internally convert to primitives and > overflow but you can't do anything to protect you from that. > > As for mixing several numebr representations in a single collection, I > think it's a problem of normalizing data but most of the time your are > either in safeland or in fastland so your representations will be > homogeneous (safehints or (boxed) primitives). > > A middleground may be to keep the semantics proposed by Rich but: > * integer literals default to safeint (unless suffixed by L for long) > * scientific notation and decimal literals default to double (unless > suffixed by M or N) > * implement a better bigint. > This, I feel, would be a win/win. +1 > Christophe > > -- > European Clojure Training Session: Brussels, 23-25/6http://conj-labs.eu/ > Professional:http://cgrand.net/(fr) > On Clojure:http://clj-me.cgrand.net/(en) --- Martin. -- 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
