>> I understand, but this library is all about state because it is about modelling long-lived entities over time as an unpredictable stream of events act on the model.
No reason why that can't be handled as a graph of nodes + a single atom. That's how you would model this in something like Loom ( https://github.com/aysylu/loom), and how I model all my dataflow graphs. Start creating recursive self-referencing data structures you're in for a world of hurt. On Thu, Mar 31, 2016 at 10:27 AM, Kenneth Tilton <k...@tiltontec.com> wrote: > > > On Thu, Mar 31, 2016 at 11:56 AM, Timothy Baldridge <tbaldri...@gmail.com> > wrote: > >> But we should mention that recursive data structures that contain refs >> are a bit of a code-smell. Your structures are no longer immutable if they >> contain refs which are mutable containers for immutable data. Something to >> think about. >> > > I understand, but this library is all about state because it is about > modelling long-lived entities over time as an unpredictable stream of > events act on the model. > > One good use case was a virtual RoboCup soccer team fed sensory data every > 100ms and responding with actions such as turning, moving, and kicking. > > So we have a long-lived soccer player instance who observes the world, > forms a strategy consisting of so many tactics and emits actions based on > the current tactic. New information comes in and the tactic itself has a > condition that says when it has succeeded or should be abandoned. etc etc. > > This is modeled with a player instance (or "model") and slots for strategy > etc, each of which is a ruled cell working off the sensory data. These > Cells depend on each other and notify their dependents when they change. > Here comes the cycle: a Cell knows the model and slot-name it is mediating, > so it is self sufficient: if someone tells me to recompute, I can do so > without also being told the instance. I can then also invoke any observers, > which are dispatched by slot name. > > Well, this much I can change: when someone asks for my value I just need > to record two pieces of information, the model and slot-name. > > Of course my next problem is that no model is an island: they exist in > trees where each node knows its parent (whassat? a DAG?). Hello cycle. > Well, I guess just recording the model did that. Anyway, the solution that > springs to mind is keeping one big dictionary keyed off a serial integer. > > Thank god for 64-bits. :) > > Thx, kt > > > > > > >> On Thu, Mar 31, 2016 at 9:53 AM, James Reeves <ja...@booleanknot.com> >> wrote: >> >>> On 31 March 2016 at 16:39, hiskennyness <kentil...@gmail.com> wrote: >>> >>>> In porting my modelling library Cells to Clojure I managed to get a >>>> stack overflow when the printer tried to print a recursive data structure* >>>> I have used in the Common Lisp version. >>>> >>>> * Basically, a ref holds a map in which some values are maps in which >>>> some values are the ref. >>>> >>>> In Lisp we have *print-depth* as well as *print-length* to deal with >>>> just this case. >>>> >>>> Is there some way I can deal with this, or are recursive data >>>> structures not really supported by Clojure? >>>> >>> >>> The same variables exist in Clojure: *print-level* and *print-length* >>> respectively. >>> >>> - James >>> >>> -- >>> 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. >>> >> >> >> >> -- >> “One of the main causes of the fall of the Roman Empire was that–lacking >> zero–they had no way to indicate successful termination of their C >> programs.” >> (Robert Firth) >> >> -- >> 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 a topic in the >> Google Groups "Clojure" group. >> To unsubscribe from this topic, visit >> https://groups.google.com/d/topic/clojure/TGtavJVzVWk/unsubscribe. >> To unsubscribe from this group and all its topics, send an email to >> clojure+unsubscr...@googlegroups.com. >> For more options, visit https://groups.google.com/d/optout. >> > > > > -- > Kenneth Tilton > Founder/Developer > TiltonTec > 54 Isle of Venice Dr > Fort Lauderdale, FL 33301 > > k...@tiltontec.com > http://tiltontec.com > @tiltonsalgebra > > 646-269-1077 > > "In a class by itself." *-Macworld* > > > -- > 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. > -- “One of the main causes of the fall of the Roman Empire was that–lacking zero–they had no way to indicate successful termination of their C programs.” (Robert Firth) -- 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.
