I'm changing a program from AWT to Swing, as proposed on the second chapter of Java Swing's book, and the panel just disappears when I do the change from Panel to JPanel. The same doesn't happen when I change from Button to JButton. It seems to be a bug, since it appears to be trivially simple to do so - just adding an extra J to the na...
I'm new to Haskell and I'd like to be able to time the runtime of a given function call or snippet of code. In Clojure I can use 'time': user=> (time (apply * (range 2 10000))) "Elapsed time: 289.795 msecs" 2846259680917054518906413212119868890148051... In Scala, I can define the function myself: scala> def time[T](code : => T) = {...
Here is an overly simplistic example for illustration: I can encapsulate an implementation detail such as using an atom for a counter: (defn make-counter ([] (make-counter 0)) ([init-val] (let [c (atom init-val)] {:get (fn [] @c) :++ (fn [] (swap! c inc))}))) But that means I need to redefine everything to add a fea...
Hello, there! I'm building an image-processing application in swing/clojure, and right now I need to develop an image panel in which I can click and compute data. Thanks to coobird, I now have a good idea on how to do it in Java, but I still don't get many issues on its integration with Clojure. Let's take a look at how coobird suggeste...
I am retrieving the HTML from the web. I get "java.lang.OutOfMemoryError: Java heap space (repl-1:3)" ;; fetch: URL -> String ;; fetch returns the string of the HTML url (defn fetch [url] (with-open [stream (. url openStream)] (let [buffer (BufferedReader. (InputStreamReader. stream))] (apply str (line-seq buffer))))) ...
I understand that they're different since one works for setting *compile-path* and one doesn't. However, I need help with why they're different. let creates a new scope with the given bindings, but binding...? Thanks! ...
(set! *warn-on-reflection* true) (proxy [javax.swing.JPanel] [] (paintComponent [#^java.awt.Graphics g] (proxy-super paintComponent g) (.fillRect g 100 100 10 10))) "Reflection warning, call to paintComponent can't be resolved" ...
The structure of my hash is (def *document-hash* {"documentid" {:term-detail {"term1" tf1 ,"term2" tf2}}) I wan to find the tf. Right now I have this. Is there a better way to do this in clojure? ;; Find tf (defn find-tf [documentid term-number] (if (nil? *document-hash* documentid) 0 (if (nil? (((*document-hash* do...
I have a passing knowledge of other Lisps (particularly Scheme) from way back when. My knowledge is pretty rusty (and was pretty basic to begin with). Recently I've been reading about Clojure. I see that it has both "symbols" and "keywords". Symbols I'm familiar with, but not keywords. Do other Lisps have keywords? How are keywords diff...
(defn get-doc-list [a-term] (map #(Integer/parseInt %)(take-nth 3 (take (* 3 3)(rest (rest a-term)))))) This function works on small lists but returns and empty sequence on larger ones. What is the problem? ...
I have a document hash which is a reference like this: (def *document-hash* (ref (hash-map))) It looks like this {"documentid" {:term-detail {"term1" count1 ,"term2" count2}, "doclen" 33}}} How do I add to this hash table?Right now I have (defn add-doc-hash [docid term-number count] (dosync (alter *document-hash* (fn [a-h...
I cant understand the documentation at all. I want a sorted map "xxx", which sorts the map according to the value. How do I do that? Thanks. ...
I have a list of keys: (1 2 3 4) I want a map with the values set to 0 like this: {1 0, 2 0, 3 0, 4 0}. How do I do that? ...
The following expression in clojure works great: (doseq [x '(1 2 3 4)] (println x)) This one gives me a nullpointer: (doseq [x '(1 2 3 4)] ((println x)(println "x"))) It produces the following output: user=> (doseq [x '(1 2 3 4)] ((println x)(println "x"))) 1 x java.lang.NullPointerException (NO_SOURCE_FILE:0) user=> (.printStackT...
I have a really really huge hash table and whenever I try to alter the hash, the entire hash is returned, which crashes my REPL. Is there a way I can ask Clojure to just set the value and return nil? Thank You. ...
I have a function (defn change-score [docid termid] (do (dosync (alter *documents-scores* assoc docid (+ 1 (*documents-scores* docid)))) nil) ) (defn vector-space[] (loop [terms (count (deref *term-hash*))] (if (zero? terms) nil (do (dorun (map (fn[docid](change-score docid terms)) (doc-...
Right Now I have ;; buffer->string: BufferedReader -> String (defn buffer->string [buffer] (loop [line (.readLine buffer) sb (StringBuilder.)] (if(nil? line) (.toString sb) (recur (.readLine buffer) (.append sb line))))) This is too slow. Edit: I have a BufferedReader when i try to do (str BufferedReader) it ...
Even looking closely over documentation on Clojure, I do not see any direct confirmation as to whether or not Clojure supports operator overloading. If it does, could someone provide me with a quick snipplet of how to overload, let's say, the "+" operator to delegate to some predefined method that we can call myPlus. I am very new to C...
Clojure is a functional lisp, reportedly not at all object-oriented, even though it runs on the JVM, a VM designed for an object oriented language. Clojure provides identical interfaces for iterating over lists and vectors by abstracting them to an interface called seq. This is even implemented internally using a Java interface called ...
Are there any CMS'es, written in functonal programming languages (lisp, haskell, f#/nemerle, scala, erlang, clojure, smalltalk) already? ...