Normally, one would not expect to be able to compare four numbers with a fifth number by bitwise or-ing the four numbers together and comparing the result to the fifth number. In the general case, this would not work. It took me three readings of the code to understand why the author *expected* it to work.
If 256 weren't a power of two, there wouldn't even be a presumption that it might work. It's a lowlevel bit-fiddling dirty-trick (attempted) solution to a higher-level problem, by no means a natural way to go about the thing at hand. Notice I did not say it isn't *the* natural way; I said it is not *a* natural way at all. Id est, it doesn't make sense.

This is why it's arguable :-) Things like this depend so much on experience with the domain and various programming styles. For me the authors intent was immediately obvious and the style a completely natural one. I can imagine writing the same code myself. I fiddle with IP addresses a great deal in various languages, and you're doing bit-mask type operations on them all of the time. I think about IP addresses and net masks in terms of bits and bytes. So, to me, boolean logic makes complete sense in this particular domain.

The problem for me is that you get bitten by Perl's DWIMary. In Perl you're trained think that Perl will do the "right thing" when given things that look like numbers. In this particular instance Perl doesn't. I think it's a good thing that the Perl 6 folk are giving us separate operators to prevent future confusion.

I can completely see your point of view, and it's nothing I'd start a religious war over, but I do think it's arguable.

In reply to Re^2: Can you spot the problem? by adrianh
in thread Can you spot the problem? by dws

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