Re^2: Moose: return null object

Are you saying you can't return undef from BUILDARGS?

That would be nice. Unfortunately, it's a fatal exception that requires catching:

#!/usr/bin/perl -w
use strict;

package test;
use Mouse;

sub BUILDARGS { return undef }

__PACKAGE__->meta->make_immutable();

my $eg = test->new();
print "All good!";  # nope...
[download]

BUILDARGS did not return a HASH reference at ./test.pl line 11.

..then return undef from new.

Yer not suppose to use your own "new", but I did try defining one and having it return undef. No errors, however, the object returned is still a hash ref, not undef:

package test;
use Mouse;

sub new { return undef }

__PACKAGE__->meta->make_immutable();

my $eg = test->new();

print $eg;
[download]

test=HASH(0x2208f08)

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Re^3: Moose: return null object by lamprecht (Friar) on Apr 18, 2011 at 16:05 UTC
The title of this thread refers to `Moose` whereas your example uses `Mouse`. Moose behaves different in this example, so this might be considered to be a bug in Mouse? `Not inlining a constructor for test since it defines its own construct +or. If you are certain you don't need to inline your constructor, specify +inline_constructor => 0 in your call to test->meta->make_immutable Use of uninitialized value $eg in print at test.pl line 14.` [download]	[reply] [d/l] [select]
Re^3: Moose: return null object by ikegami (Patriarch) on Apr 18, 2011 at 16:28 UTC
Yer not suppose to use your own "new" That's an overstatement. No errors, however, the object returned is still a hash ref Sure, because you told Moose to use its own `new` instead of yours. `package Module; use Mouse; sub new { return undef } __PACKAGE__->meta->make_immutable( inline_constructor => 0 ); print __PACKAGE__->new();` [download] I think it used to warn when `new` existed and you inlined the constructor. It really should. (Upd: OH! Moose does warn, it's Mouse that doesn't. Mouse-- lamprecht++ )	[reply] [d/l] [select]
Re^4: Moose: return null object by halfcountplus (Hermit) on Apr 18, 2011 at 17:11 UTC
I think it used to warn when new existed and you inlined the constructor. It really should. (Upd: OH! Moose does warn, it's Mouse that doesn't. Mouse-- lamprecht++ ) Yeah, that might have given me a clue, but I wouldn't count the lack of helping friendless as a genuine bug. Anyway, it works, so there was this something I missed, hooray. Thanks y'all.	[reply]