On Wed, Jun 15, 2011 at 2:41 PM, Colin Yates <colin.ya...@gmail.com> wrote: > In Clojure, if I understand correctly, the preferred way would be to use a > map (or defstruct) with keys such as :name and :age. These are then > retrieved as (person :name) and (person: age) etc. > My question is if I suddenly decided that one of those values is best > implemented as a calculation, how can I seamlessly implement that. By > seamless I mean implement it without updating any consumers of a person?
> For example, if I changed the age property to be the result of a function, > I could either replace the value of age with a function that calculates age > or write a function(person)->age. > Both of those are disruptive to the consumers of person. > I understand that clojure is about explicitly distinguishing between state > and functions, but I see this as a high price to pay. Have I missed > something? The OO in me is saying "well, never introspect a map directly, > rather provide get-X(person) functions" but that is very very noisy. But that's more or less what you'd have to do. If age might be calculated in some more complex manner, now or in the future, you want something like (defn age [person] (:age person)) or whatever. -- Protege: What is this seething mass of parentheses?! Master: Your father's Lisp REPL. This is the language of a true hacker. Not as clumsy or random as C++; a language for a more civilized age. -- 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
