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functionperlclasscallinstance

Perl - call an instance of a class

Is there way to catch the event of calling an instance of a Perl class?

my $obj = ExampleClass->new();
$obj(); # do something without producing error

I would like to be able to handle this from within the class/module definition. Something similar to the __call__ method in Python, or the __call metamethod in Lua.

Solution

  • I'm still not sure what the use case is, but you can overload the class to handle code dereferencing.

    package ExampleClass;
use overload '&{}' => \&__call__;   # Or an anon sub.
sub new {
   bless {@_}, shift;
}
sub __call__ {
    sub { warn "calling an instance event" };
}

package main;
my $obj = ExampleClass->new;
$obj->();
&$obj();      # same as $obj->()

    Typical output:

    $ perl 44956235.pl
calling an instance event at 44956235.pl line 7.
calling an instance event at 44956235.pl line 7.