ns :import / reflection
Hello, I have two newbie questions: First - (ns test (:import (java.io File))) I can use File like this (let [file (File. filename)]))) When using this import (ns test (:import (java.io.File))) I get an "Unable to resolve classname: File" which I don't understand. Second -- With this small piece of code (ns test (:import (java.io File))) (set! *warn-on-reflection* true) (if (nil? *command-line-args*) (println "No command line arguments given.") (let [filename (first *command-line-args*)] (println filename) (let [file (File. filename)]))) I get an "Reflection warning, X:\workspace\ClojureTest\bin\test.clj:9 - call to java.io.File ctor can't be resolved." which I also don't understand. Thanks in advance, Marcel -- 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
"-function" special?
Hi there, in some clojure examples I see function names with a leading dash like -main() -getFoo() (in backing bean) -setBar() (in backing bean) Are these functions with leading dash anything special? Or is this dash required for some interop? I didn't find any documentation about it. Thanks in advance, Marcel -- 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
Re: ns :import / reflection
Yes, that did the trick. Thank you. Am 21.02.2012 02:53, schrieb Sean Corfield: On Sat, Feb 18, 2012 at 1:29 PM, ClusterCat wrote: (ns test (:import (java.io File))) This says import the File class from the package java.io (ns test (:import (java.io.File))) Try: (ns test (:import java.io.File)) (let [filename (first *command-line-args*)] (println filename) (let [file (File. filename)]))) I get an "Reflection warning, X:\workspace\ClojureTest\bin\test.clj:9 - call to java.io.File ctor can't be resolved." which I also don't understand. Clojure relies on type hints to avoid reflection - introspecting Java class types to figure out calls. If you add ^String in let binding for filename, it should remove the warning: (let [^String filename (first *command-line-args*)] ... HTH? -- 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
function order
In search for a Clojure bencode implentation, I found the following source code. (defn- decode-list [stream] (loop [result []] (let [c (char (.read stream))] (if (= c \e) result (recur (conj result (decode stream (int c (defn decode [stream & i] (let [indicator (if (nil? i) (.read stream) (first i))] (cond (and (>= indicator 48) (<= indicator 57)) (decode-string stream indicator) (= (char indicator) \i) (decode-number stream \e) (= (char indicator) \l) (decode-list stream) (= (char indicator) \d) (decode-map stream (taken from http://nakkaya.com/2009/11/02/decoding-bencoded-streams-in-clojure/) The example functions do not work for me, because decode tries to call decode-list which tries to call decode. This leads me to the following questions: 1. What is the (technical) reason the compiler can't just "look up" all functions before using them? 2. What is the standard way or best practice to work around such constructs? Greetings, Marcel -- 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
