Hi Mark, 2009/10/21 Mark Nutter <manutte...@gmail.com>: > > (defn blank? [s] (every? #(Character/isWhitespace %) s))
<snip> > user=> (defn hexchar? [c] (re-find #"[0-9A-Fa-f]" c)) <snip> > user=> (defn hex? [s] (every? #(hexchar? %) s)) > #'user/hex? > nil > user=> (hex? "a") > #<CompilerException java.lang.ClassCastException: java.lang.Character > cannot be cast to java.lang.CharSequence (NO_SOURCE_FILE:0)> If you'll look at the argument types of the two predicates, you'll notice that Character/isWhiteSpace takes a char as an argument whereas you predicate takes a String (or more specifically a CharSequence). The (every?) form is trying to call (hexchar?) with char arguments and it blows up. One way to fix this would be to produce a string out of c: (defn hexchar? [c] (re-find #"[0-9A-Fa-f]" (str c))) but you should really change hexchar? into something more elegant. A few style pointers: - predicates, i.e. functions that end in ?, should really return a boolean - you can replace #(hexchar? %) with hexchar? in the every? form. This doesn't work in the Character/isWhitespace case because that's a Java call. > Mark HTH! -- ! Lauri --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
