RE: Moose Type Constraints violations to warnings?

Looks like the code was mangled.  Look at attached.

---
Edward J. Allen III




> From: [email protected]
> To: [email protected]
> Subject: RE: Moose Type Constraints violations to warnings?
> Date: Fri, 10 Jun 2011 12:41:41 -0700
> 
> 
> it seems to me that you have two problems:
> 1)  You want to know that your value is always a number, so you add a constraint.
> 2)  Your users will not always enter the correct value.
> 3)  You want to KNOW what the bad value was.
> So I would separate out the input attribute and the used attribute.  Moose (and mouse) makes this easy!  Check out this example (I wrote it using 5.10 Perl, mainly as I am trying to practice using it...):
> 
> #### Start
> use Mouse;use Mouse::Util::TypeConstraints;package MyApp::Room;use Carp qw(cluck);use Scalar::Util qw(looks_like_number);
> use feature 'switch';
> # Subtype and coercionsubtype 'Price'    => as 'Num';
> coerce 'Price'    => from 'Str'    => via {        given($_) {            # Anything like a number is OK            when (looks_like_number $_) {                return $_;            }            # $9.99  is ok.            when(/ \A \$(\d+\.?\d+?) \z /xms) {                return $1;            }            # $.99 is ok            when(/ \A \$(\d+?\.\d+) \z /xms) {                return $1;            }            # Complain about anything else.            default {                cluck 'Price must be a number!  Setting to $0.00';                return 0;            }         }     };
> has 'price_in' => (    is => 'rw',    perdicate => 'has_price_in',    trigger => sub {        my ($self,$val) = @_;        $self->price($val);    });
> has 'price' => (    is => 'rw',    isa => 'Price',    coerce => 1,);
> 
> package main;
> use feature 'say';
> # Says 3.50my $room = MyApp::Room->new( price_in => '3.50' );say "Room price: " . $room->price();
> # Says 1000$room->price_in('1000');say "Room price: " . $room->price();
> # Says 0 and complains$room->price_in('cheap');say "Room price: " . $room->price();
> 
> 
> #### END
> ---
> Edward J. Allen III
> 
> 
> 
> 
> > Date: Fri, 10 Jun 2011 13:37:36 -0400
> > Subject: Re: Moose Type Constraints violations to warnings?
> > From: [email protected]
> > To: [email protected]
> > CC: [email protected]; [email protected]
> > 
> > On Fri, Jun 10, 2011 at 1:14 PM, Buddy Burden <[email protected]> wrote:
> > > Ovid,
> > >
> > > On Fri, Jun 10, 2011 at 3:06 AM, Ovid <[email protected]> wrote:
> > >> When I declare a parameter as follows:
> > >>
> > >>
> > >>     has 'some_val' => (
> > >>         is  => 'rw',
> > >>         isa => 'Int',
> > >>     );
> > >>
> > >> Later if I do $object->some_value("foobar"), it blows up with a stack trace because of the type constraint violation.
> > >>
> > >> Without using signal handlers, is there some way I can convert that exception into a warning except when something like $ENV{HARNESS_ACTIVE} is true? Preferably on a per-attribute basis?
> > >
> > > Is it possible that Jesse's answer to my question here:
> > >
> > >    http://www.mail-archive.com/[email protected]/msg01464.html
> > >
> > > could help?  I know it isn't exactly the same problem that you're
> > > describing, but it seems that if there's a way to solve one, there
> > > must be a way to solve the other as well.  Possibly the code of the
> > > module he mentions would be illuminating.
> > >
> > > Apologies if this isn't actually helpful.
> > 
> > Karen also suggested MooseX::Constructor::AllErrors but discarded it
> > because it was Moose only. A Mouse port would probably be pretty
> > simple.
> > But it only covers the constructor case.
> > 
> > For accessors, if the issue is that you "don't want type constraints
> > to throw out *everything*" you'll need to show a better example of the
> > parsing code because I'm not sure how a judicious use of Try::Tiny
> > wouldn't be the natural solution there. Accessors never really operate
> > on the entire object, so you'd only throw an exception for a specific
> > attribute. Wrapping the block in Try::Tiny will leave the object in a
> > partial state (whatever had been mutated until the exception was
> > thrown) and give you an error message you could then dispatch with.
> > 
> > The particular phrase Ovid referred to in the Moose docs was written a
> > *long* time ago when Stevan still believed that you could potentially
> > safely turn off runtime type checks. My impression is that he's
> > re-considered this idea now. It also applies to Moose and not Mouse.
> > Mouse has it's own development community and goals.
> > 
> > -Chris
>

package MyApp::Room;
use Mouse;
use Mouse::Util::TypeConstraints;
use Carp qw(cluck);
use Scalar::Util qw(looks_like_number);

use feature 'switch';

# Subtype and coercion
subtype 'Price'
    => as 'Num';


coerce 'Price'
    => from 'Str'
    => via { 
        given($_) {                 
            # Anything like a number is OK
            when (looks_like_number $_) {     
                return $_;
            }
            # $9.99  is ok.
            when(/ \A \$(\d+\.?\d+?) \z /xms) {
                return $1;
            }
            # $.99 is ok
            when(/ \A \$(\d+?\.\d+) \z /xms) {
                return $1;
            }
            # Complain about anything else.
            default {
                cluck 'Price must be a number!  Setting to $0.00';
                return 0;
            }
         }
     };

has 'price_in' => (
    is => 'rw',
    perdicate => 'has_price_in',
    trigger => sub {
        my ($self,$val) = @_;
        $self->price($val);
    }
);

has 'price' => (
    is => 'rw',
    isa => 'Price',
    coerce => 1,
);


package main;

use feature 'say';

my $room = MyApp::Room->new( price_in => '3.50' );

say "Room price: " . $room->price();

$room->price_in('1000');

say "Room price: " . $room->price();

$room->price_in('cheap');

say "Room price: " . $room->price();