| And to be completely clear, I'm not complaining about the design decision in Clojure. I'm just trying to really understand what the design is, what are the trade-offs and where the confusion might come from.
conj is what is known as a leaky abstraction. Leaky abstractions aren't always bad, sometimes they are made leaky by choice. A leaky abstraction is one that reveals and requires you to be aware of its underlying concrete implementation. Generally an abstraction is made leaky when the implementation details are in fact very important to the success of using the abstraction for real world use cases. This I think was the choice made for conj. You can see that from the docstring itself: "The 'addition' may happen at different 'places' depending on the concrete type." The docstring directly points you towards knowing that the concrete types add the element in different places. That knowledge is leaky. But, its also very important, because in many real world use cases, performance of addition will matter, and order of addition will matter, and you'll want to choose the correct concrete type to get the order you want with the performance you need. Generally, leaky abstractions are more annoying to use for simple use cases, since often you want to say, I don't care about all the little details, but as your use case grows, the devil sometimes shows up in thise details, and suddenly, that leakyness becomes a blessing. So, did Clojure made the right choice in making conj leaky? Hard to say, and the answer is probably personal and opinionated. That said, I'm sure the intent was to force the details onto the user, and force them to be aware of their implications when using conj. -- 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.
