Hello Mark, 2 questions / suggestions :
* couldn't step 2) be computed outside function b, and then my-data be replaced by new-struct ? This way, if you have several flavors of function b, you will not have to repeat the code in steps 1) and 3) in each of those flavors of b ? And then the problem you have disappear because new-struct is known in advance by the function calling swap! * may I challenge your use of atom ? When I read your post, I had an orange light flashing "warning, warning", so I can't resist do this :-) : from the information you give, it seems to me that my-atom is like a repository. Wouldn't this repository be consulted by other functions ? In this case, don't you want to sometimes ensure (via the ensure function) that the repository remains in the same state for the duration of some transactions ? Or write some commute code to add/remove/update parts of it from within a transaction ? Then shouldn't your atom really be a ref ? Regards, -- Laurent 2009/3/21 Mark Volkmann <r.mark.volkm...@gmail.com> > > I'm using an atom to hold a sorted-map whose keys are integer ids and > values are a particular kind of struct. > I have a function, call it "a", that adds an entry to this map. > It contains just this line: > > (swap! my-atom b my-data) > > "b" is a function that: > 1) determines the next available id by getting the last entry in the > sorted-map and adding 1 > 2) creates new-struct using my-data > 3) creates and returns a new map by calling (assoc current-map id > new-struct) > > All that seems simple enough. > However, I need to be able to get the new-struct that was just added > so I can pass it to other functions. > In this case, swap! returns the new map that has become the new value > of the atom, not the value that was just added to the map. > > I'm looking for a suggestion on how I can get new-struct. > > -- > R. Mark Volkmann > Object Computing, Inc. > > > > --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
