On Dec 22, 2010, at 6:52 AM, Alyssa Kwan wrote: > The issue is where do I specify that: > (undo-fn ...patch...) => (fn [] (reset! visible-evidence-of-a-side- > effect :happened!))
The code you quoted is that specification. It doesn't matter that undo-fn is a multimethod. Here's what the notation of the test says: When called with an arbitrary patch, undo-patch will produce a particular side effect. It does that because it uses undo-patch, which--when given that arbitrary patch--returns a function that produces that side effect. It also calls remove-patch with the given patch. undo-patch can return anything it wants. We don't care. > > (fact "The patch's undo-fn is called for its side effect and the patch is > forgotten" > (let [visible-evidence-of-a-side-effect (atom nil)] > (undo-patch ...patch...) => anything > (provided > (undo-fn ...patch...) => (fn [] (reset! > visible-evidence-of-a-side-effect :happened!)) > (remove-patch ...patch...) => :nothing-of-interest) > @visible-evidence-of-a-side-effect => :happened!)) ----- Brian Marick, Artisanal Labrador Contract programming in Ruby and Clojure Author of /Ring/ (forthcoming; sample: http://bit.ly/hfdf9T) www.exampler.com, www.exampler.com/blog, www.twitter.com/marick -- 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
