Re: Java classes in Kawa

[Chris Bitmead <chris at bitmead dot com>]

Hi,

No matter what I try I seem to get "Argument to 
java.util.Collections.sort has wrong type".
I'm using kawa-cvs. What is wrong?

(define-simple-class <comparator> (<java.util.Comparator>)
 (function init-keyword: function:)
 ((compare (o1 :: <java.lang.Object>) (o2 :: <java.lang.Object>)) :: <int>
  ((slot-ref (this) 'function) o1 o2)))

(define (sort function list)
 (let ((comparator (make <comparator> function: function)))
   (invoke-static <java.util.Collections> 'sort list comparator)
   list))

(define (comp x1 x2) (cond ((< x1 x2) -1) ((> x1 x2) 1) (else 0)))
(define lu (vector 12 8 7 44 -1 -7 9 8))
(define ls (sort comp lu))
(display ls)


Per Bothner wrote:

> Chris Bitmead wrote:
>
> > I was trying to implement a sort function in kawa.
>
> The following works to sort vectors:
>
> (define-simple-class <comparator> (<java.util.Comparator>)
>  (function init-keyword: function:)
>  ((compare (o1 :: <java.lang.Object>) (o2 :: <java.lang.Object>)) :: 
> <int>
>   ((slot-ref (this) 'function) o1 o2)))
>
> (define (sort function list)
>  (let ((comparator (make <comparator> function: function)))
>    (invoke-static <java.util.Collections> 'sort list comparator)
>    list))
>
> (define (comp x1 x2) (cond ((< x1 x2) -1) ((> x1 x2) 1) (else 0)))
>
> (define lu (vector 12 8 7 44 -1 -7 9 8))
>
> (define ls (sort comp lu))
>
> Sorting lists doesn't yet work, because some methods are not
> implemented.  I'm looking at that now.