...Just trying to understand the rationale between Clojure's design here. As I gradually get deeper into Clojure, I've been highly impressed by how well thought-out everything is, so I'm sure there is a very good reason for this one too. The question is:
Why are Clojure's built-in collections *seqable* rather than being *seqs*? Or equivalently: Why do Clojure's built-in collections support (seq) rather than (first) and (rest)? A few possible reasons I can think of: 1. From reading the implementation of classes like PersistentHashMap, I can see that running over a map using a seq (basically a persistent cursor into the map) should be significantly faster, and create less garbage, then generating a succession of smaller and smaller maps (right down to an empty one) would be. 2. (seq) returns nil on an empty collection, which can naturally be used in a conditional. 3. (seq) works on things like Java arrays and Strings which can't be modified to implement ISeq. Have I missed any? More importantly, can someone close to the core team identify *which* of these was the deciding factor in this design decision? -- 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
