On Tue, Jan 27, 2009 at 7:43 AM, Chouser <chou...@gmail.com> wrote: > > On Tue, Jan 27, 2009 at 8:51 AM, Mark Volkmann > <r.mark.volkm...@gmail.com> wrote: > > > > Are these statements correct? Actually, I know some are correct > > because I just looked though the source. Hopefully others that haven't > > will find this interesting. > > > > Symbol objects have a String name and a String namespace name, but no > value. > > Var objects have references to a Symbol object, a Namespace object and > > an Object object which is its "root value". > > Namespace objects have a reference to a Map that holds associations > > between Symbol objects and Var objects. > > In Clojure, the term "interning" typically refers to adding a > > Symbol-to-Var mapping to a Namespace. > > Those all sound right to me, with the (very minor) caveat that > Namespaces also have a aliases map. > > > Why don't Symbol objects have a reference to a Namespace object > > instead of a String that is a Namespace name? > > The namespace part of a symbol doesn't have to refer to any existing > namespace. This is useful for example when using the symbol as its > own value. > > user=> (namespace 'foo/bar) > "foo" > > The namespace part can even be 'nil', which is probably the most > common case for symbols created by the reader: > > user=> (def expr (read (java.io.PushbackReader. (java.io.StringReader. > "(+ 1 2)")))) > user=> (first expr) > + > user=> (namespace (first expr)) > nil
This nil namespace seems a bit odd. Wasn't expr created in the user namespace? > > Or even just: > > user=> (namespace 'zipmap) > nil > > --Chouser > > > > --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
