I second: using seq to test for emptiness is only one half of the idiom, the second half is to bind and to destructure (usually with if-let) the returned value.
Christophe On Sat, May 11, 2013 at 12:08 PM, Chris Ford <christophertf...@gmail.com>wrote: > IMHO it's a bit subjective, but empty? is defined as (not (seq coll)), so > using (not (empty? coll)) is really saying (not (not (seq coll))), which > feels a bit backwards. > > Using seq also plays nicely with if-let: > > (if-let [foo (seq "hey")] (print foo)) > (if-let [foo (seq "")] (print foo)) > > Chris > > > On 11 May 2013 12:48, Kelker Ryan <theinter...@yandex.com> wrote: > >> Here's an example. >> >> user=> (if (seq []) (println 1)) >> nil >> user=> (if (seq [1]) (println 1)) >> 1 >> nil >> >> >> 11.05.2013, 18:40, "Kelker Ryan" >> > (seq coll) will return a true value if the collection isn't empty. It >> will also return nil (false) if it is. >> > >> > 11.05.2013, 17:37, "Nico Balestra" <nicobales...@gmail.com>: >> > >> >> I'm not sure this question has been asked already, but I really want >> to know the "principle" behind (not (empty? coll)) not being idiomatic. >> >> >> >> I find it much more readable than (seq coll) and I don't understand >> why (empty?) exists if it's not idiomatic. But my real doubt is: >> >> >> >> What's the "idiom" in (seq coll)? >> >> >> >> Thanks and sorry if the question sounds a bit pedantic :) >> >> >> >> Nico >> >> >> >> "It is better to have 100 functions operate on one data structure >> than to have 10 functions operate on 10 data structures" - A.J. 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