How about this:
has 'min' => (
is => 'rw',
isa => 'Int',
default => sub { NEGATIVE_INFINITY },
trigger => sub {
my ( $self, $val ) = @_;
carp "min is > max" unless $val <= $self->max;
}
);
has 'max' => (
is => 'rw',
isa => 'Int',
default => sub { POSITIVE_INFINITY },
trigger => sub {
my ( $self, $val ) = @_;
carp "max is < min" unless $val >= $self->min;
}
);
No BUILD needed. Consistency checked by the triggers whenever min and
max are set...
Besides defining negative and positive infinity, the only problem I
see is if both min and max are set at the same time, as in the
constructor. I don't know which error you'd get if the object was
initialized like this:
my $foo = Foo->new(
min => 1,
max => -1,
);
Charles Alderman
----- Original Message -----
From: Guillaume Rousse <[EMAIL PROTECTED]>
Sent: Mon, 14 Jul 2008 23:15:49 +0200
Re: checking consistency between attributes
Hello list.
What's the best way to check consistency between attributes values ? Is
there anything better than a dedicated BUILD method, such as:
use Moose;
use Carp;
has 'min' => (is => 'rw', isa => 'Int');
has 'max' => (is => 'rw', isa => 'Int');
sub BUILD {
my ($self, $params) = @_;
my ($max, $min) = ($self->max(), $self->min());
croak "max < min" if defined $max && defined $min && $max < $min;
}
--
Guillaume Rousse
Moyens Informatiques - INRIA Futurs
Tel: 01 69 35 69 62
