Re: (series of swap! on atom) ==> single swap!

Hi t x and Jan, what about performing the side effect part of the function adding a watch? (They are no more in alpha with the upcoming 1.6.) Cheers, Luca Il giorno lunedì 17 febbraio 2014 09:29:57 UTC+1, t x ha scritto: > > Hi Jan, > > Thanks for your explanations. > > I have no idea how

Re: (series of swap! on atom) ==> single swap!

Hi Jan, Thanks for your explanations. I have no idea how I managed to completely misunderstand clojure/atom for the past few years -- I suspect it's because I never use clojure/STM, and as a result, I've never had an atom roll back on me. I've decided to switch to agents. Thanks again f

Re: (series of swap! on atom) ==> single swap!

Hi t x, I think, that lock-free approach an it's semantics is more in line with other Clojure reference types such as refs. It also encourages you to only use pure functions for state transitions, among other things, such as significant performance benefits in comparison with lock based approach

Re: (series of swap! on atom) ==> single swap!

Hi Jan, You're right. I'm wrong. I'm grateful you pointed this out -- this would have otherwise been impossible to debug. === To everyone: Why can swap! be retried? This confuses me -- to implement swap!, why can't we * have a lock * ensure that only one swa

Re: (series of swap! on atom) ==> single swap!

I'm afraid your understanding of atom swap! operations is not quite correct -> update function must (or should) be pure as well. See the documentationfor swap!, update function could be potentially called multiple times if there are more t

Re: (series of swap! on atom) ==> single swap!

I believe that's the STM approach, which has the advanrtage of: * can synchronize across multiple pieces of data but has the disadvantage of: * work must be "pure" since it can be retried * possibly less efficient due to possibility of retrying In the example I posted above, I only need

Re: (series of swap! on atom) ==> single swap!

You can use a ref instead of an atom. And use dosync with multiple alter, so everything is safely inside a transaction. On Feb 16, 2014 2:04 PM, "t x" wrote: > Hi John, > > Your solution is perfectly valid and optimal for the problem I > described above. > > > Unfortunately, I forgot to menti

Re: (series of swap! on atom) ==> single swap!

Hi John, Your solution is perfectly valid and optimal for the problem I described above. Unfortunately, I forgot to mention an additional constraint: sometimes I do: (let [ foo (:some-selector @data-atom) ] (swap! data-atom update-in [:other-selector] ... )) which the -> doesn't quite wo

Re: (series of swap! on atom) ==> single swap!

On Sat, Feb 15, 2014 at 6:04 PM, t x wrote: > > (defn what-I-want [] > (with-atom some-atom > assoc-in ... > assoc-in ... > update-in ...)) > I often do something like this and don't find it too ugly: (swap! my-atom #(-> % (assoc-in [:k] v) (upda

(series of swap! on atom) ==> single swap!

Hi, Consider the following block of code: ## Sample Code (ns test) (def some-atom (atom {:tag :language :name "Clojure" :better-than ["scheme" "java" "ruby" "python"]})) (defn demo-func [] (swap! some-atom assoc-in [:name] "Clojure 1.6") (swa