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Re^2: Safer monkey-patching

by moritz (Cardinal)
on Jan 19, 2012 at 08:07 UTC ( #948714=note: print w/replies, xml ) Need Help??

in reply to Re: Safer monkey-patching
in thread Safer monkey-patching

in Example::ErrorList, provide a method that returns list item class name, and instantiate objects of that name.

You can also make that an attribute (plus accessor, if you want), so that subclassing isn't even necessary. If you use blessed hash references as objects, and do not create the hash key in the default case, there's not even a memory penality to be paid unless you deviate from the default.

An example for a read and write accessor could be

sub error_class { my $self = shift; my $default = 'Example::Error'; if (@_) { my $new = shift; if ($new eq $default) { delete $self->{error_class} } else { $self->{error_class} = $new' } } $self->{error_class} // $default }

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[jdporter]: one prog I have has a UI which allows to input a bit mask
[jdporter]: currently it expects the bitmask to be in the form of a hex number, e.g. 0x0101
[jdporter]: but I'd like to let the user specify it as individual bits, i.e. 0b0000000100000001
[jdporter]: there is no bit/binary equivalent of hex, right?
[jdporter]: I guess that the most direct way of doing it is with some magical incantation involving unpack or whatever
[jdporter]: let me google that for me ;-)
[jdporter]: hex points explicitly to oct, which does the job. :-D
[jdporter]: omg, I f love Perl!
[choroba]: say unpack 'H*', pack 'B*', $mask =~ /0b([01]+)/;

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