Have you looked at core.memoize, which uses core.cache under the hood? It allows for pluggable caching strategies that might suit your use-case.
https://github.com/clojure/core.memoize On Sat, May 3, 2014 at 10:27 PM, Mike Fikes <mikefi...@me.com> wrote: > Are there common techniques or idioms for achieving structural sharing > when composing data where equivalences exist? > > (My motivation is to reduce heap usage for a particular problem I'm > working on that involves a lot of repeated data.) > > As a specific example, consider sharing equivalent map values: > > (def m1 {:a [1 2]}) > > (def m2 (assoc m1 :b [1 2])) > > > (identical? (m2 :a) (m2 :b)) > > ;; => false > > > For this simple example, I can force sharing by introducing a variant of > assoc which looks at existing values: > > > (defn assoc-id [map key val] (assoc map key (get (apply hash-set (vals > map)) val val))) > > > And using it results in a map with two identical values: > > > (def m3 (assoc-id m1 :b [1 2])) > > > (identical? (m3 :a) (m3 :b)) > > ;; => true > > > But, of course, this approach could get to be expensive and/or unwieldy if > not done carefully. > > > So, I was wondering if there are general techniques in this area. I'm sure > I'm not the first to come across it. We already get this automatically > for boxing of small integers: > > > (identical? 5 5) > > ;; => true > > > (identical? 500 500) > > ;; => false > > > So I suppose I'm essentially looking for the same idea but for larger > non-primitive "values". > > > -- > 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 > --- > You received this message because you are subscribed to the Google Groups > "Clojure" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to clojure+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/d/optout. > -- 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 --- You received this message because you are subscribed to the Google Groups "Clojure" group. To unsubscribe from this group and stop receiving emails from it, send an email to clojure+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
