Clojure avoid as much as possible making nil or emptiness a special case requiring the caller to test it before calling a function.
I would like this to remain like that after years of testing null in Java before doing anything else on a object to prevent exceptions. This is a design decision taken years ago. If you really need to test emptiness, empty? exists exactly for this purpose. Luc > Right now > > (last []) => nil > (last [nil]) => nil > > So there is no way to differentiate these two (except with some > emptiness checking). In my opinion (last []) should throw an > exception, because that's when last does not apply. From another point > of view, there are two cases: > > 1. The local semantics requires the collection not to be empty. > Throwing an exception here will remove the burden of manual checking. > > 2. The local semantics allows the collection to be empty, in that case > the caller needs to do > (when-not (empty? c) (last c)). > > case 1 is the "normal case" with higher probability, so the burden of > checking should be on the second case. > > Your opinion? > > Note this is rather academic because it probably is too late do > anything about it at this stage. But it may help future cases. > > -- > 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 > -- Softaddicts<lprefonta...@softaddicts.ca> sent by ibisMail from my ipad! -- 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
