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Re: RFC: pack()ing long words

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David Cantrell
August 13, 2012 10:16
Re: RFC: pack()ing long words
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On Mon, Aug 13, 2012 at 01:51:03PM +0200, H.Merijn Brand wrote:

> Counterintuitive in that order
> l4 is 4 longs, so if the 4 in your example matches the 4 in l4, I'd
> guess that
>   X5>4
> would be more intuitive

But then you have a problem if someone wants native endian-ness - you
can't tell whether X54 is a single word of 54 bytes, or four words of
five bytes each.

Leon's suggestion of putting the word length in {curlies} works nicely.

> I kinda like your approach though. What about bits? Why restrict to
> multiple of 8 bits?

Hmmm ... and just have X{40}4 instead of X{5}4 for a five byte
(== 40 bits) word.  I haven't looked at the source (and am somewhat
terrified to do so TBH) but I can see that getting a bit tricky.  If you
consume just three bits with X3, does the next template thingy, and all
the ones after it, have to start and stop half way through a byte?

Maybe that's something to allow for in the syntax, but leave the
implementation until even later.

David Cantrell | Bourgeois reactionary pig

Cum catapultae proscriptae erunt tum soli proscript catapultas habebunt

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