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Date: Thu, 27 Jul 2006 15:43:27 +0200
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Subject: Re: [PHP-DEV] dec*(), *dec(), base_convert() and negative numbers
From: mike@php.net (Michael Wallner)

Matt W wrote:

> That's why I'm assuming negative numbers aren't "really" supported
> now (not in any form with base_convert()), but it's simply a side
> effect of wanting to handle *positive* numbers between LONG_MAX and
> ULONG_MAX.  e.g. when doing dechex(4294967173) that's a PHP double,
> but it gets converted to long (becomes -123), and finally unsigned
> long (recovering 4294967173).  IOW, after convert_to_long() in dec*()
> it doesn't know if -123 or 4294967173 was passed.  Make sense?
> (Actually, it doesn't, that's my point. :-))

For your computer 0xffffff85 is -123 and 4294967173.  It's just how
you look on it.

> So after more thinking, I figure when upgrading dec*() to handle any
> number, absolute value should be used (then int(123) would be
> returned in my example).  Unless the all the functions are changed to
> properly accept/return negatives... I personally don't care either
> way on that.

No way. Why should hexdec(dechex(-123)) return +123?

-- 
Michael