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copied!<p>Use a <a href="http://clojure.github.com/clojure/clojure.core-api.html#clojure.core/for">for comprehension</a>, these yield lazy sequences.</p> <p>Here's the code for you. I've taken the time to make it runnable on the command line; you only need to replace the name of the parsed XML file.</p> <p><strong>Caveat 1:</strong> avoid def-ing your variables. Use local variables instead.</p> <p><strong>Caveat 2:</strong> this is the Java API for XML, so there objects are mutable; since you have a lazy sequence, if any changes happen to the mutable DOM tree while you're iterating, you might have unpleasant race changes.</p> <p><strong>Caveat 3:</strong> even though this is a lazy structure, the whole DOM tree is already in memory anyway <em>(I'm not really sure about this last comment, though. I think the API tries to defer reading the tree in memory until needed, but, no guarantees)</em>. So if you run into trouble with big XML documents, try to avoid the DOM approach.</p> <pre><code>(require ['clojure.java.io :as 'io]) (import [javax.xml.parsers DocumentBuilderFactory]) (import [org.xml.sax InputSource]) (def dbf (DocumentBuilderFactory/newInstance)) (doto dbf (.setValidating false) (.setNamespaceAware true) (.setIgnoringElementContentWhitespace true)) (def builder (.newDocumentBuilder dbf)) (def doc (.parse builder (InputSource. (io/reader "C:/workspace/myproject/pom.xml")))) (defn lazy-child-list [element] (let [nodelist (.getChildNodes element) len (.getLength nodelist)] (for [i (range len)] (.item nodelist i)))) ;; To print the children of an element (-> doc (.getDocumentElement) (lazy-child-list) (println)) ;; Prints clojure.lang.LazySeq (-> doc (.getDocumentElement) (lazy-child-list) (class) (println)) </code></pre>

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