Newbie so go gentle please :). I am an experienced OO Java developer (decade +) considering jumping fence to a functional language, and clojure is pretty high up on the list for a number of reasons.
I am so used to defining everything as objects which are sealed units of state and behaviour that I am struggling to see how to solve the same problem with clojure. I desperately wish somebody would write a "domain driven design with clojure" :). In brief, in OO state is exposed via a well defined API. That state may be simple properties (values) or it may be calculations (functions). And critically, the decision as to whether it is a value or a function is an implementation concern. The Java Bean spec defines accessors for properties of a class, behind which lies the logic of how to retrieve that state. So, the very common Person class will expose get/setName(), get/setAge() etc. and as a consumer I have no idea how the results are calcualted. 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. That's enough for now - this is, I expect, the first of many cries for help :) Thanks in advance to all who reply! -- 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
