memoize, or delay maybe On Sun, Jan 20, 2013 at 10:29 PM, AtKaaZ <atk...@gmail.com> wrote:
> memoize? > > > On Mon, Jan 21, 2013 at 7:27 AM, Larry Travis <tra...@cs.wisc.edu> wrote: > >> One of the neat things about Clojure (maybe all functional languages) is >> that functions can be defined either extensionally or intensionally. How >> can one create a Clojure structure that mixes these two types of definition? >> >> That is, I would like to define a function f that saves its result the >> first time it is called against any particular argument so that if and when >> f is later called against the same argument, it does a look-up via a hash >> map rather than repeating a possibly expensive computation. I think I see >> how to do this with a ref to a mutable map (where, given an argument k, f >> would first try to find (f k) in the map but, if k is not currently a key >> of the map, the function would compute the value v = (f k) and then, in >> addition to returning v, add the entry <k v> to the map as a side effect. >> But this seems ugly. Is there some way to do what I want here without >> making explicit use of refs? >> >> Lazy-seqs don't give me what I want because the arguments to be given to >> f don't occur in any kind of predictable sequence. >> >> --Larry >> >> -- >> 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+unsubscribe@**googlegroups.com<clojure%2bunsubscr...@googlegroups.com> >> For more options, visit this group at >> http://groups.google.com/**group/clojure?hl=en<http://groups.google.com/group/clojure?hl=en> >> > > > > -- > I may be wrong or incomplete. > Please express any corrections / additions, > they are encouraged and appreciated. > At least one entity is bound to be transformed if you do ;) > > -- > 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 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
