Re: operator

[Luke Palmer]

Markus Laire writes:
> [EMAIL PROTECTED] kirjoitti:
> >Please,
> >I have a question if exists in Perl somethink like keyword
> >'operator' in C++ ?
> 
> That will exist in perl6.

And to quite a larger extent.  Not only can you overload existing
operators, you can make up whatever operator name you like.

> >for example we can write in C++ :
> >class A {
> >A() { printf("Constructor of object class A\n"); }
> >~A() { printf("Destructor of object class A\n"); }
> >};
> >A &operator + (A &a1, A &a2) { printf("Addition\n"); }
> >A &operator * (A &a1, A &a2) { printf("Multiplication\n"); }
> >
> > int main() {
> > A a,b,c;
> > c = (a+b*a);
> > }
> 
> Using these as reference:
> 
> http://dev.perl.org/perl6/synopsis/S06.html
> http://dev.perl.org/perl6/synopsis/S12.html
> 
> (I don't understand how to create constructor & destructor)
> I think equivalent perl6-code would be:
> 
> class A {
>   # place constructor here

    submethod BUILD() {
        say "Constructor of class A";
    }

>   # place destructor here
    submethod DESTROY() {
        say "Destructor of class A";
    }
> }
> 
> sub infix:<+> (A $a1, A $a2) { print("Addition\n"); }
> sub infix:<*> (A $a1, A $a2) { print("Multiplication\n"); }

I expect you need "multi" on those subs, to avoid redefining the
existing operators (not without it yelling at you a bit, though).

    multi sub infix:<+> (A $a1, A $a2) { say "Addition" }
    multi sub infix:<*> (A $a1, A $a2) { say "Multiplication" }

> my A $a; # note, I'm not sure how to write this on one line
> my A $b;
> my A $c;

Just:

    my A ($a, $b, $c);

Luke

> $c = ($a + $b * $a);