On Fri, Feb 13, 2009 at 8:01 PM, Phil Hagelberg <p...@hagelb.org> wrote:
>
> wubbie <sunj...@gmail.com> writes:
>> Hi, do we have labels equiv. in clojure?
>> The code below is from OnLisp. Trying to convert to clj file,
>> but have minor difficulties.
>
> You can use "let" since variables and functions are kept in the same
> namespace.
This is true, but this...
> (defn count-instances [obj lsts]
> (let [instances-in (fn [lst]
> (if (cons? lst)
> (+ (if (= (first lst) obj) 1 0)
> (instances-in (rest lst)))
> 0))]
> (map instances-in lsts)))
...doesn't work. You can't refer to the 'let' local from within the
fn definition. You can however give the fn a name, like thisfn:
(defn count-instances [obj lsts]
(let [instances-in (fn thisfn [lst]
(if (seq lst)
(+ (if (= (first lst) obj) 1 0)
(thisfn (rest lst)))
0))]
(map instances-in lsts)))
That works, but is not very Clojurey. Just for the record, I might do
it more like:
(defn count-instances [obj lsts]
(map #(count (filter #{obj} %)) lsts))
--Chouser
--~--~---------~--~----~------------~-------~--~----~
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
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
-~----------~----~----~----~------~----~------~--~---
