On Sat, Jul 9, 2011 at 10:10 AM, stu <stuart.hungerf...@gmail.com> wrote:
> Hi, > > I'd like to make use of Java classes implementing the Java2D > PathIterator interface: > > > http://download.oracle.com/javase/6/docs/api/java/awt/geom/PathIterator.html > > Which leads to a serious impedance mismatch between immutable Clojure > data structures and the iterator's approach of calling next() until > isDone() and using currentSegment() to retrieve the point > coordinates. > > I'd guess this kind of iterator is widely used in the Java world, so > can some kind person point to an example of Clojure code using a Java > iterator in this way? > > Thanks in advance, > > Stu > Clojure has a built in function, iterator-seq, which converts a java.util.Iterator to a lazy-seq. Lazy-seq's keep a copy of each data item that they have grabbed from the iterator, so they hide the mutability of Iterators. http://clojuredocs.org/clojure_core/clojure.core/iterator-seq Your interface doesn't subclass java.util.Iterator though, so you would need to make something similar. I haven't tested this, but maybe something like this: (defn pathiterator-seq [i] (when-not (.isDone i) (lazy-seq (.next i) (let [arr (make-array Double/TYPE 6) type (.currentSegment i arr)] (cons {:type type :coords (into [] arr)} (pathiterator-seq i)))))) -- Dave -- 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
