perl-PerlX-Maybe - Return a Pair Only If They Are Both Defined
Moose classes (and some other classes) distinguish between an attribute being unset and the attribute being set to undef. Supplying a constructor arguments like this:
my $bob = Person->new(
name => $name,
age => $age,
);
Will result in the 'name' and 'age' attributes possibly being set to undef (if the corresponding '$name' and '$age' variables are not defined), which may violate the Person class' type constraints.
(Note: if you are the _author_ of the class in question, you can solve this using MooseX::UndefTolerant. However, some of us are stuck using non-UndefTolerant classes written by third parties.)
To ensure that the Person constructor does not try to set a name or age at all when they are undefined, ugly looking code like this is often used:
my $bob = Person->new(
defined $name ? (name => $name) : (),
defined $age ? (age => $age) : (),
);
or:
use PerlX::Maybe;
my $bob = Person->new(
(name => $name) x!!(defined $name),
(age => $age) x!!(defined $age),
);
A slightly more elegant solution is the 'maybe' function.
- Sources inherited from project openSUSE:Backports:SLE-15-SP5
- Download package
-
Checkout Package
osc -A https://api.opensuse.org checkout openSUSE:Leap:15.5:ARM/perl-PerlX-Maybe && cd $_
- Create Badge
Source Files
Filename | Size | Changed |
---|---|---|
PerlX-Maybe-1.202.tar.gz | 0000018346 17.9 KB | |
cpanspec.yml | 0000000669 669 Bytes | |
perl-PerlX-Maybe.changes | 0000001559 1.52 KB | |
perl-PerlX-Maybe.spec | 0000002626 2.56 KB |
Comments 0