When you find non-idiomatic code in clojure's impl, the reason is almost always performance. In this case the clojure.string version is more performant since it saves: 1) the allocation of a lazy seq over the characters of the string 2) the allocation of a java.lang.Character for every char in the string, thanks to clojure's ability to generate code for unboxed primitives
2013/1/15 Thomas <th.vanderv...@gmail.com> > Hi all, > > In Stuart Halloway's book (Programming Clojure) is a wonderful example of > the succinctness of Clojure where he compares the Apache Commons > implementation of the isBlank method ( > http://commons.apache.org/lang/api-2.5/src-html/org/apache/commons/lang/StringUtils.html#line.227) > with a Clojure equivalent which is a single line: > > (defn blank? [s] (every? #(Character/isWhitespace %) s)) > > I have used this example a few times to show colleagues the difference > between Java and Clojure and why (IMHO) the Clojure solution is so much > nicer. Earlier today I looked at clojure.string and noticed that it had > blank? in it and looking at the source ( > https://github.com/clojure/clojure/blob/f30995c86056959abca53d0ca35dcb9cfa73e6e6/src/clj/clojure/string.clj#L225) > I noticed that the actual implementation in Clojure is surprisingly similar > to the Java one (verbose, several if's, a loop etc.) > > Is there any particular reason for this? It is performance? What is wrong > with Stuarts example? (I just checked it and it correct as far as I can > tell). > > And a second question: What other examples are people using to demonstrate > the advantages of Clojure (in an elevator pitch style equivalent) > > TIA, > > Thomas > > -- > 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 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
