[parenscript-devel] How to call constructor?

[Miron Brezuleanu]

Hello,

I have a problem with the Parenscript from the latest Quicklisp update
(2012-02-08).

Before this update: I'm trying to instantiate an object using 'new'.
Since I wanted to have 'var obj = new ClassName();' and not 'var obj =
new ClassName' I used '(ps ((new -class-name)))' which did what I
wanted (generate 'new ClassName()').

After the update: '(ps ((new -class-name)))' generates '(new
ClassName)()' which is wrong. Luckily for me, 'new ClassName'
generated by '(new -class-name)' works.

What do I do if I need to generate something like 'new Person(age,
shoeSize)'? (i.e. I don't know how to pass parameters to new - and I
could not find a description of any special syntax in the manual).
'(ps (new -person age shoe-size))', fails with an error which seems to
imply that there can be only one argument to new (when printing :-) ).

I managed to convince the printer to accept '(ps (new -person age
shoe-size))' and generate 'new Person(age, shoeSize)' using the code
in this patch:

diff --git a/src/printer.lisp b/src/printer.lisp
index c37e10c..d7e26f4 100644
--- a/src/printer.lisp
+++ b/src/printer.lisp
@@ -235,7 +235,14 @@ vice-versa.")
 (defprinter ps-js:negate (x)
   "-"(print-op-argument op x))

-(defprinter (ps-js:delete ps-js:typeof ps-js:new ps-js:throw) (x)
+(defprinter ps-js:new (&rest x)
+  "new "
+  (ps-print (car x))
+  "("
+  (psw (format nil "~{~a~^, ~}" (mapcar #'symbol-to-js-string (cdr x))))
+  ")")
+
+(defprinter (ps-js:delete ps-js:typeof ps-js:throw) (x)
   (print-op op)" "(print-op-argument op x))

 (defprinter (ps-js:return) (&optional (x nil x?))


Thanks for any suggestions,
-- 
Miron Brezuleanu