Yes, that's better. Glad you like the idea. Does anybody not named Stuart also want to see this added to Clojure? ;-)
Stuart > On Oct 3, 3:13 pm, Stuart Halloway <[EMAIL PROTECTED]> wrote: >> (defmacro ?. >> "like .. but drops out on null object" >> ([x form] >> `(. ~x ~form)) >> ([x form & more] >> `(if-let x# (. ~x ~form) (.? x# [EMAIL PROTECTED])))) > > Interesting -- I like it. It doesn't seem to be totally compatible > with "..", though: > > user=> (?. System (getenv "SHELL") (startsWith "/bin") getClass > getName) > java.lang.Exception: Unable to resolve symbol: startsWith in this > context (NO_SOURCE_FILE:62) > > Also, if-let could give the wrong result in the (admittedly unlikely) > situation that one of the methods returns Boolean.FALSE. > Here's another take: > > (defmacro ?.. > "like .. but stops and returns nil if any method returns nil" > ([x form] > `(.. ~x ~form)) > ([x form & more] > `(let [x# (?. ~x ~form)] > (if (nil? x#) nil > (?. x# [EMAIL PROTECTED]))))) > > user=> (?.. System (getenv "SHELL") (startsWith "/bin") getClass > getName) > "java.lang.Boolean" > user=> (?.. System (getenv "FOO") (startsWith "/bin") getClass > getName) > nil > > -the other Stuart > > > --~--~---------~--~----~------------~-------~--~----~ 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 [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/clojure?hl=en -~----------~----~----~----~------~----~------~--~---
