Hi, Am 26.12.2009 um 14:45 schrieb Heinz N. Gies:
> > On Dec 26, 2009, at 2:37 , Nicolas Buduroi wrote: > >> >> I'll have a look at this, it would certainly make this function more >> idiomatic to Clojurians. >> >> Thanks for the suggestion. > > I've another one I like even better, it get's a bit away from mapping over n > list but it could achiev the same: > > (defn extend-tupel [default & lists] > (if (some (complement empty?) lists) > (cons > (map (fn [l] (if (empty? l) default (first l))) lists) > (lazy-seq (apply extend-tupel default (map next lists)))) > nil)) > > This takes a default value and N lists, then creates s tupels form this lists > untill all are empty, filling the ones that are empty before the rest with > the default value. You could use destruction in your map to make it look like > mapping over multiple lists. I like this better since each list will only > walked once, this is especially nicer in my eyes when it are lazy lists that > need to be evaluated each time the list is accessed. Here is a more idiomatic (and fully lazy) version using the fnil function proposed by Rich here: http://groups.google.com/group/clojure/msg/f251cfd9baab440a (defn extend-tupel [default & lists] (lazy-seq (let [seqs (map seq lists)] (when (some identity seqs) (cons (map (fnil first default) seqs) (apply extend-tupel default (map rest seqs))))))) Sincerely Meikel -- 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
