Meta Configuration of Package perl-PerlX-Maybe

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Meta Configuration of Package perl-PerlX-Maybe

<package name="perl-PerlX-Maybe" project="openSUSE:Factory">
  <title>perl-PerlX-Maybe - Return a Pair Only If They Are Both Defined</title>
  <description>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-&gt;new(
    name =&gt; $name,
    age =&gt; $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-&gt;new(
    defined $name ? (name =&gt; $name) : (),
    defined $age ? (age =&gt; $age) : (),
 );

or:

use PerlX::Maybe;

my $bob = Person-&gt;new(
    (name =&gt; $name) x!!(defined $name),
    (age  =&gt; $age)  x!!(defined $age),
 );

A slightly more elegant solution is the 'maybe' function.</description>
  <devel project="devel:languages:perl" package="perl-PerlX-Maybe"/>
</package>

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