Nicer hex-unpack

tritt has asked for the wisdom of the Perl Monks concerning the following question:

Hi, Is there a nicer way of doing this?

use constant XXX => 0xcccc;

($self->{auth_mode}, $val) = unpack('H4a*',$val);
$self->{auth_mode} = hex($self->{auth_mode});

given ($self->{auth_mode})
{
when (XXX) {do_smthg;}
}
[download]

Thanks in advance :)

Comment on Nicer hex-unpack Download Code

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Re: Nicer hex-unpack by Corion (Patriarch) on Jul 12, 2011 at 09:05 UTC
Why convert from hex strings to a number when in the end you compare anyway? Unless you use fancy bitmask arithmetic, just stay with strings: `use constant XXX => 'cccc'; $self->{auth_mode} = lc $val; given ($self->{auth_mode}) { when (XXX) { ... } };` [download] Note that the change from numeric to string comparisons might prove problematic if you have multiple locations where you check for equality with `==` (and no test suite that smokes out such situations).	[reply] [d/l] [select]
Re: Nicer hex-unpack by TomDLux (Vicar) on Jul 14, 2011 at 19:33 UTC
I would use `Readonly my $XXX => 0xcccc;` rather than `use constant`, and of course equivalent numbers are equivalent without needing explicit conversion. What is it you find clumsy? As Occam said: Entia non sunt multiplicanda praeter necessitatem.	[reply] [d/l] [select]