Dan,
I have to ponder this one, it would basically mean we need to wrap a
loop around the coerce statement which would keep trying until it
matched the type. I have concerns about the performance impacts of
this, and of the possibility of unintended coercions happening since
types/coercions are essentially global.
We have discussed a (deep_coerce => 1) option for attributes, which
originally meant that it would coerce inside collections too (coerce
the elements of an ArrayRef, or of a HashRef), but it could also mean
"keep coercing until you cant anymore" too.
- Stevan
On Jan 25, 2008, at 2:21 PM, Dan Harbin wrote:
Below I've included a snippet of my type constraints module where I
declare my own personal type constraints and coercions.
I'm trying to make it where I can have an accessor of type YAML, where
I can assign it a string representing a file name. This file name
gets coerced into an InputFile, which gets coerced into a YAML.
This gives me an error like so:
Attribute (file) does not pass the type constraint (YAML) with
'config.yml' at Moose/Meta/Attribute.pm line 244
Is there any way to chain or nest the constraints like I've tried
below?
Thanks,
Dan
-------
use Moose::Util::TypeConstraints;
use IO::File;
use YAML;
subtype 'InputFile'
=> as 'Object'
=> where { $_->isa('IO::Handle') };
coerce 'InputFile'
=> from 'Str'
=> via {
my $io = IO::File->new();
$io->open($_, 'r') or IOException->throw( error => "Unable to open
file $_: $!" );
return $io;
};
subtype 'YAML'
=> as 'Ref';
coerce 'YAML'
=> from 'InputFile'
=> via {
my $data = do{ local($/); $_->getline };
YAML::Load($data);
};
1;
