Skip to main content
13 events
when toggle format what by license comment
Mar 6, 2016 at 18:11 history edited J. M.'s missing motivation
edited tags
Dec 18, 2014 at 23:30 history tweeted twitter.com/#!/StackMma/status/545722930240684032
Dec 18, 2014 at 22:34 vote accept Murta
Dec 18, 2014 at 20:20 comment added Leonid Shifrin @Murta Ok, done as requested.
Dec 18, 2014 at 20:19 answer added Leonid Shifrin timeline score: 31
Dec 18, 2014 at 20:01 comment added Leonid Shifrin @alancalvitti Can't say, too little information. Associations can hold millions of key-value pairs easily, but are not too memory-efficient. It all depends on how large the total number of key-value pairs is, and whether or not it is feasible to store them in an Association in memory. There are other factors too.
Dec 18, 2014 at 19:41 comment added Murta @LeonidShifrin nice, it works!.. Lookup[Association@{1 -> "test", 2 -> "test"}, {1, 2, 3}, Null] do the work. I believe you should answer this.
Dec 18, 2014 at 18:41 comment added alancalvitti ... or would have to rebuild on Erlang.
Dec 18, 2014 at 18:39 comment added alancalvitti @LeonidShifrin, on this subject, the FTC is planning for microsec resolution for Nasdaq ("Tape C") transaction stream. In a few large hospitals there are ~10k RTLS+RFID tags on which real time monitoring is desired - coupled w/ ParallelCombine and GroupBy tasks - can Association and Dispatch scale up to these real time analytics challenges (think visulization like Tableau).
Dec 18, 2014 at 16:36 comment added Leonid Shifrin If you are not going to change your list of rules after you construct them, Dispatch is pretty good. The main difference is that it is cheap to add new key-value pairs to associations, constructing new associations - not so with Dispatch. You can somewhat emulate the action of Dispatch-ed rules on a list of elements, by using Lookup with Associations. Lookup can take a list of keys. It has also optional argument for a default value. Not sure if it can do both at the same time, don't remember.
Dec 18, 2014 at 16:17 comment added FJRA Association keys cannot be patterns (they behave like they had Verbatim), that's the main difference with common rules. Try _Integer /. Association@{_Integer -> Null}, you will get the Null value.
Dec 18, 2014 at 16:00 answer added Daniel W timeline score: 10
Dec 18, 2014 at 14:54 history asked Murta CC BY-SA 3.0