I went through the rest of my Project Euler code. In addition to even?, there are some functions in clojure.contrib that are also much slower in 1.3 Alpha 1.
clojure.contrib.math -> expt (Clojure 1.2) user=> (time (doseq [x (range 100000)] (expt x 2))) "Elapsed time: 119.417971 msecs" (Clojure 1.3) user=> (time (doseq [x (range 100000)] (expt x 2))) "Elapsed time: 10314.24357 msecs" clojure.contrib.math -> sqrt (Clojure 1.2) user=> (time (doseq [x (range 100000)] (sqrt x))) "Elapsed time: 176.063438 msecs" (Clojure 1.3) user=> (time (doseq [x (range 100000)] (sqrt x))) "Elapsed time: 16323.254492 msecs" For now, I've switched to using sqrt in the clojure.contrib.generic.math-functions module (no slow-down in 1.3). That module also has a pow function, which I was going to use as a replacement for expt. But pow doesn't seem to handle very large numbers: user=> (pow 999 999) Infinity So for now I'm using this as a temporary stop-gap: (defn expt [base pow] (reduce *' (repeat pow base))) Also found that sequences from clojure.contrib.lazy-seqs that used to produce arbitrarily large numbers in 1.2 no longer do so in 1.3: (Clojure 1.2) user=> (nth (fibs) 100) 354224848179261915075 user=> (nth (powers-of-2) 100) 1267650600228229401496703205376 (Clojure 1.3) user=> (nth (fibs) 100) ArithmeticException integer overflow clojure.lang.Numbers.throwIntOverflow (Numbers.java:1575) user=> (nth (powers-of-2) 100) 0 ... probably also because of 1.3's changes to numeric operations (http://dev.clojure.org/display/doc/Enhanced+Primitive+Support). I guess the take-away is that while playing with 1.3, be prepared to deal with performance and/or overflow issues when using existing numeric code (whether your own or someone else's) that doesn't yet take into account the changes to numeric operations. -- 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
