Hi Ryan, In Clojure a var can refer to a function, or something else, and what a var refers to can change at runtime.
You can call def with no arguments, or call declare, to def the var name with no initial binding: (declare mysecond) -> #'user/mysecond (defn myfirst [] (mysecond)) -> #'user/myfirst ; bind mysecond later... Since you are reading through PCL anyway you might want to look at the chapters I ported to Clojure: http://blog.thinkrelevance.com/2008/9/16/pcl-clojure Cheers, Stu > I'm reading through Practical Common Lisp as a way to get more > familiar with Lisp. In Chapter 4 I came across a stumbling block in > the section "S-expressions As Lisp Forms." Towards the end of that > section it says > > "To determine what kind of form a given list is, the evaluator must > determine whether the symbol that starts the list is the name of a > function, a macro, or a special operator. If the symbol hasn't been > defined yet--as may be the case if you're compiling code that contains > references to functions that will be defined later--it's assumed to be > a function name." > > If I try to define the following function in the Clojure REPL I will > get an exception saying it was unable to resolve the symbol, but that > same method will simply give me a warning in CL stating that the > method mysecond is undefined. > > (defn myfirst [] (mysecond)) > > At first I thought maybe this has something to do with the fact that > Clojure is a Lisp-1 vs. a Lisp-2, but the above is legal in MIT > Scheme. > > So why is the above form not legal in Clojure? I would think it might > come in handy to define a function that relies on something currently > not-yet-defined. Why is this the appropriate behavior? > > Excuse my noise if this is already explained in the docs, or is > obvious. > > -Ryan > > --~--~---------~--~----~------------~-------~--~----~ 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 [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/clojure?hl=en -~----------~----~----~----~------~----~------~--~---
