I knew I was missing something...!! Thanks all for your help! :) On Aug 27, 12:19 am, Scott Moonen <smoo...@andstuff.org> wrote: > Hi Soura. I think you have an extra set of parentheses in your second > example, on the line with dosync. It should read: > > (defn foo2 [n] > (let [r (ref n)] > #(dosync > (alter r + %) @r))) > > -- Scott > > > > > > On Wed, Aug 26, 2009 at 2:40 PM, Sourav <soura.ja...@gmail.com> wrote: > > > Hi, > > > I'm new to clojure and came from a Lisp background. While learning I > > clojure I came accross the two different ways of creating anonymous > > functions ((fn ...) and #(...)). I tried to construct the accumulator > > function in clojure using these forms and this is what I wrote (this > > might seem naive but I'm just a beginner :) > > > 1. > > > (defn foo [n] > > (let [r (ref n)] > > (fn [i] > > (dosync > > (alter r + i) @r)))) > > And it works fine: > > > user> (def f (foo 10)) > > #'user/f > > user> (f 1) > > 11 > > user> (f 1) > > 12 > > > 2. > > (defn foo2 [n] > > (let [r (ref n)] > > #((dosync > > (alter r + %) @r)))) > > > This does not work: > > user> (def f (foo2 10)) > > #'user/f > > user> (f 1) > > ; Evaluation aborted. > > java.lang.ClassCastException: java.lang.Integer cannot be cast to > > clojure.lang.IFn (NO_SOURCE_FILE:0) > > [Thrown class clojure.lang.Compiler$CompilerException] > > > However, another different function defined below just works: > > > user> (defn bar [n] > > #(+ n %)) > > #'user/bar > > user> (def b (bar 10)) > > #'user/b > > user> (b 1) > > 11 > > > Obviously I might be missing something... Please help. > > --http://scott.andstuff.org/ | http://truthadorned.org/- Hide quoted text - > > - Show quoted text -
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