I think I have an interesting problem. I'm trying to create a macro
that generates a class AND a post-init method for the class. Something
like:
;;; create the macro
(defmacro definstance [name & body]
(let [post-init (gensym "postinit")]
`(do
(defn ~(symbol (str "-" post-init)) [this#]
(println "here we'll do something very interesting with
'body' "))
(gen-class
:name ~name
:extends SomeSuperClass
:post-init ~post-init
))))
;;; generate a class with it
(definstance somepackage.MyClass (println "here is the body"))
The macro returns a defn form, for defining the post-init, and a gen-
class form, for defining the class itself. Since a macro can only
return one form, I wrapped the two forms in a single do form.
I can compile the above into a jar. I can then reference it from
another Java project and I can actually use the class. If I run the
Java project from the command line, everything works perfectly.
If I expand the macro with a (macroexpand '(definstance
somepackage.MyClass (println "here is the body"))), put the expansion
in a Clojure source file, and use that from a Java web project (from
within a Servlet) everything still works perfectly.
But when I try to use the above source directly from a web
application, I get an UnsupportedOperationException from the
constructor of the class, because it cannot find a method called
postinit31.
Summarised: the above code works as is in a Java command line
application. The explicit macro expansion works fine in a web
application called from a Servlet. But if I use the above code
literally in a web application, BANG.
It DOES work if I split the single macro into two macros, one for the
gen-class and one for the defn. But that is not what I want.
Can anybody help me out here?
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