On Sat, Jul 30, 2011 at 1:00 AM, Petr Gladkikh <petrg...@gmail.com> wrote:
> I tried this since I have not used macroses for real problem so far.
> And it actually works.
> But I do not understand why it works.
> I have class:
> class Foo {
> public String s;
> public int v;
> public String toString() { return "{" + s + "," + v + "}"; }
> }
>
> Then in Clojure:
> (defsetter abcde [:s :v])
> (let [afoo (actialpackage.Foo.)]
> (set-abcde afoo {:s "S" :v 42})
> (println afoo))
>
> But at the moment (defsetter abcde [:s :v]) is expanded nothing is
> known about actual class.
> So it is not clear to me why this works but giving field names at
> runtime does not.
>
> Can anyone clarify this?
> Maybe this wokrs because in this case compiler can infer type of java
> object at compile time?
The macro expands into field-accessing code. If the compiler infers
the type, this becomes fast bytecode to access the fields. Otherwise
it becomes slowish reflection calls, but still works.
--
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Master: Your father's Lisp REPL. This is the language of a true
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