(proxy class-and-interfaces args & fs)
class-and-interfaces - a vector of class names
args - a (possibly empty) vector of arguments to the superclass
constructor.
f => (name [params*] body) or
(name ([params*] body) ([params+] body) ...)
Expands to code which creates a instance of a proxy class that
implements the named class/interface(s) by calling the supplied
fns. A single class, if provided, must be first. If not provided it
defaults to Object.
The interfaces names must be valid interface types. If a method fn
is not provided for a class method, the superclass methd will be
called. If a method fn is not provided for an interface method, an
UnsupportedOperationException will be thrown should it be
called. Method fns are closures and can capture the environment in
which proxy is called. Each method fn takes an additional implicit
first arg, which is bound to 'this. Note that while method fns can
be provided to override protected methods, they have no other access
to protected members, nor to super, as these capabilities cannot be
proxied.
Source
(defmacro proxy
"class-and-interfaces - a vector of class names
args - a (possibly empty) vector of arguments to the superclass
constructor.
f => (name [params*] body) or
(name ([params*] body) ([params+] body) ...)
Expands to code which creates a instance of a proxy class that
implements the named class/interface(s) by calling the supplied
fns. A single class, if provided, must be first. If not provided it
defaults to Object.
The interfaces names must be valid interface types. If a method fn
is not provided for a class method, the superclass methd will be
called. If a method fn is not provided for an interface method, an
UnsupportedOperationException will be thrown should it be
called. Method fns are closures and can capture the environment in
which proxy is called. Each method fn takes an additional implicit
first arg, which is bound to 'this. Note that while method fns can
be provided to override protected methods, they have no other access
to protected members, nor to super, as these capabilities cannot be
proxied."
{:added "1.0"}
[class-and-interfaces args & fs]
(let [bases (map #(or (resolve %) (throw (Exception. (str "Can't resolve: " %))))
class-and-interfaces)
[super interfaces] (get-super-and-interfaces bases)
compile-effect (when *compile-files*
(let [[cname bytecode] (generate-proxy super interfaces)]
(clojure.lang.Compiler/writeClassFile cname bytecode)))
pc-effect (apply get-proxy-class bases)
pname (proxy-name super interfaces)]
;remember the class to prevent it from disappearing before use
(intern *ns* (symbol pname) pc-effect)
`(let [;pc# (get-proxy-class ~@class-and-interfaces)
p# (new ~(symbol pname) ~@args)] ;(construct-proxy pc# ~@args)]
(init-proxy p#
~(loop [fmap {} fs fs]
(if fs
(let [[sym & meths] (first fs)
meths (if (vector? (first meths))
(list meths)
meths)
meths (map (fn [[params & body]]
(cons (apply vector 'this params) body))
meths)]
(if-not (contains? fmap (name sym))
(recur (assoc fmap (name sym) (cons `fn meths)) (next fs))
(throw (IllegalArgumentException.
(str "Method '" (name sym) "' redefined")))))
fmap)))
p#)))