I am new to clojure, but it seems very interesting. Has anyone thought about allowing "update in place" for situations where it is safe?
Suppose you have (def y (tripleit x)) and you know that there is only a single reference to x at this point, then it would be safe to implement it as "y takes on the storage of x and this is multiplied by 3 in-place". Well, I should say it's safe as long as "x" loses scope at this point. The fact that y has gained its storage and done an update in place shouldn't bother anyone or cause any loss in purity. This is what "uniqueness types" are used for in the "Clean" functional lanugage. (And logic language Mercury uses "unique modes".) Now I realize there is the question in Clojure of "how do we know whether it's unique". Clean does it via the type system. But one could have other mechanisms for ensuring uniqueness. One would be to keep a runtime track of references and only allow an update-in-place primitive in the case of a single reference. If this were attempted when multiple references existed, a runtime error would occur. Has anyone thought about this kind of update-in-place methodology? It seems to be one of the reasons why both Clean and Mercury achieve good performance. Perhaps there are good reasons why this approach is not workable in clojure (or not useful), but I'd be interested to hear why. Thanks, Mark. --~--~---------~--~----~------------~-------~--~----~ 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 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 -~----------~----~----~----~------~----~------~--~---
