Re: Method/attribute chaining

Hi,

I've written up the case I found as a test, please feel free to add  
it if it's useful. All tests pass apart from the last one which tests  
attribute chaining. Tested on Pugs 6.2.5.

#!/usr/bin/pugs

use v6;
use Test;

plan 7;

#Setup
class Foo {
    has $.bar is rw;
}

my $foo  = Foo.new;
my $foo2 = Foo.new;

#Sanity check
isa_ok($foo,  'Foo');
isa_ok($foo2, 'Foo');

#Setup chain
$foo.bar  = $foo2;
$foo2.bar = 'baz';

#Sanity check part two
is($foo2.bar, 'baz', '... got the right value in $foo2');
is($foo.bar =:= $foo2, 1, '... $foo is storing $foo2');

#Extract last part of chain
my $foo3 = $foo.bar;

#and check its fine
is($foo3 =:= $foo2, 1, '... we can retrieve $foo2 as $foo3');
is($foo3.bar, 'baz', '... got the right value in $foo3');

#Check chaining
lives_ok{
    $foo.bar.bar == 'baz' ;
}, '... attribute chaining is OK';



On 24 May 2005, at 12:52, Adrian Taylor wrote:

> Hi,
>
> I have seen similar weirdness and added a couple of tests over the
> weekend, whilst simultaneously forgetting to mention it on IRC:
>
> class Foo {
>   method noargs () { 42 }
>   method callsmethod2 { .noargs(); }
> }
>
>  $val = $foo.callsmethod2()
>
> dies. (t/oo/method/instance.t)
>
> It appears to be something to do with whether the methods are declared
> with brackets (method callsmethod2 versus method callsmethod2()).
>
> Maybe this is related.
>
> Cheers
>
> Ade
>
> Alex Gutteridge wrote:
>
>
> > Hi,
> >
> > Just playing around with pugs 6.2.5 OO and couldn't work this out:
> >
> > class Bowl {
> >         has $.fish  is rw;
> >         has $.water is rw;
> > }
> > class Fish {
> >         has $.bowl    is rw;
> >         has $.eyes    is rw;
> > }
> >
> > my $bowl   = Bowl.new;
> > my $blinky = Fish.new;
> >
> > $bowl.water  = 'Murky';
> > $blinky.eyes = 3;
> >
> > $bowl.fish   = $blinky;
> > $blinky.bowl = $bowl;
> >
> > $bowl.water.say;
> > $blinky.eyes.say;
> >
> > my $blinkys_bowl = $blinky.bowl;
> > $blinkys_bowl.water.say;
> >
> > my $fishy = $bowl.fish;
> > $fishy.eyes.say;
> >
> > $bowl.fish.eyes.say;
> > $blinky.bowl.water.say;
> >
> > The output I get:
> >
> > Murky
> > 3
> > Murky
> > 3
> > *** No compatible subroutine found: "&eyes"
> >     at Desktop/testOO.pl line 27, column 1-20
> >
> > Am I missing something in the syntax when I try to chain the
> > attribute methods? Or is this not implemented in pugs yet?
> >
> > Thanks for any help.
> >
> > Alex Gutteridge
> >
> > EBI
> > Wellcome Trust Genome Campus
> > Hinxton
> > Cambs CB10 1SD
> > UK
> >
> > Tel: 01223 492546
> > Email: alexg@xxxxxxxxx

Alex Gutteridge

EBI
Wellcome Trust Genome Campus
Hinxton
Cambs CB10 1SD
UK

Tel: 01223 492546
Email: alexg@xxxxxxxxx