Re: operator overloading

From:

Mark Space <markspace@sbc.global.net>

Newsgroups:

comp.lang.java.programmer

Date:

Sat, 10 May 2008 12:01:42 -0700

Message-ID:

<ximVj.2375$ah4.1318@flpi148.ffdc.sbc.com>

Stefan Ram wrote:

Patricia Shanahan <pats@acm.org> writes:

Infix arithmetic operator version: (n * (2*a1 + (n-1)*d))/2.
This version is a very simple transformation of the mathematical notation.
Anyone up to writing this out in prefix method call notation?

On can always use a program to transform an infix expression like

BigDecimal( "2" )+ BigDecimal( "3" )* BigDecimal( "4" )

to a prefix expression like

( new java.math.BigDecimal( "2" ) ).add( ( new java.math.BigDecimal( "3" ) ).multiply( new java.math.BigDecimal( "4" ) ) )

I was thinking the same thing. What is going in Java 7 is even more
support for scripting. I wonder if that could be used to translate from
infix to prefix.

import some.package.mathscript;

public class MatUtil {

   public Matrix transform( Matrix a, Matrix b )
   {
     Matrix result;

     @<mathscript>
        result = (-a)*b;
     @</mathscript>

     return result;
   }
}

Looks a bit like JSP. Hmm, I wonder if that's a good thing. The need
to make your own scripting engine should prevent the most cavalier abuse
of this type of construct, I think.

P.S. Does anyone else get surprised when their mail client doesn't
auto-indent? I always am.