Re: When is "z" != "z" ?

2006/6/6, Robert Cummings <robert@interjinn.com>:

On Tue, 2006-06-06 at 14:06, Martin Alterisio wrote: 2006/6/6, Robert Cummings <robert@interjinn.com>:

You must have missed this post: http://marc.theaimsgroup.com/?l=php-general&m=114945456908350&w=2

Yes, I haven't read that post. That algorithm has an error, an

overflow

on a

signed char, and that's implementation issue not a design issue.

Actually it's a design issue. C uses a numeric datatype that is bound

by

a specific number of bits. It could just have well have been designed with a numeric datatype that had arbitrary length. The design decision was made to keep it close to the machine. However, the point I was making is that dealing with fringe cases is a necessity when you want

to

ensure your code is robust.

I haven't thought this carefully, you're right to point that is a design issue since compilers and interpreters have to take into account the actual data representation in the design stage. Still, an overload is an known issue and that can be caught easily. If you assume that the ++ and comparison operator can be used with any type of object in a for loop, and they don't follow the expected contrains an iterator shoud have then the problem will be less apparent, as the issue is not considered a misuse but a normal function of the data type. So there you go, by your own words, knowing the way the system works and the edge cases is integral to proper use of the language. Thus when 'z'++ == 'aa' the semantics while not necessarily ubiquitous, fall under the language's well defined modus operandi :)

You lost me there. Can you explain it a little bit further?