Hi,
I am looking for something which operates similarly as doseq but in
case of more than one binding traverses every sequence only one. I.e.
wanted result:
(doseq [x '(A B C) y '(1 2 3)] (println (list x y)))
should produce:
(A 1)
(B 2)
(C 3)
OK I know that in this particular case there are some shorthands like
using
(doseq [x (indexed '(A B C))] (println (list (second x) (inc (first
x)) )))
but I am looking for something general.
Be honest I am starting to write a macros:
(defmacro foreach [bind-vect expr]
`(if (< 0 (count ~(second bind-vect)))
(loop [~(symbol (first bind-vect)) (first ~(second bind-vect))
proc#
(rest ~(second bind-vect))]
(do
~expr
(if (< 0 (count proc#))
(recur (first proc#) (next proc#)))))))
and for two bindig pairs
(defmacro foreach2 [bind-vect expr]
`(if (< 0 (count ~(second bind-vect)))
(loop [~(symbol (nth bind-vect 0)) (first ~(nth bind-vect 1))
coll1# (rest ~(nth bind-vect 1))
~(symbol (nth bind-vect 2)) (first
~(nth bind-vect 3))
coll2# (rest ~(nth bind-vect 3))]
(do
~expr
(if (< 0 (count coll1#))
(recur (first coll1#) (next
coll1#) (first coll2#) (next
coll2#)))))))
but I am not sure whether this is a good solution?
On the other hand do you have an idea how to make foreach2 macro more
general, handling any length of binding vector?
--
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
