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From: "Jean-Pierre Rosen" <rosen@adalog.fr>
Newsgroups: comp.lang.ada
Subject: Re: Mneson announcement and help request
Date: Fri, 4 Jun 2004 09:30:39 +0200
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Date: 2004-06-04T09:30:39+02:00
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> "Randy Brukardt" <randy@rrsoftware.com> wrote in message
> news:-NSdneXjh7wndyLdRVn-vw@megapath.net...
> > My point was that as long as you keep the exception handler and raising
> out
> > of the loop (which is certainly true for EOF), it can be quite efficient.
> In
> > the normal case (where you read many characters before reaching the end of
> > the file), it's almost always better to handle the exception. That's
> because
> > one exception raise/handling pair is a lot cheaper than 10,000 function
> > calls, especially one as expensive as EOF.

I always use the exception mechanism for another reason:
In the presence of a "malformed" file (i.e. one where the last line has no line terminator before EOF), you may have an unexpected
End_Error even if End_Of_File was false. Of course, this is outside Ada semantics, but it's the real world that text files are
sometimes being typed by human beings....

So, in short:
1) when you do a Get, it will have to (more or less) check EoF anyway
2) if you check EoF, you must still be prepared to catch End_Error anyway

=> I never check EoF any more.

-- 
---------------------------------------------------------
           J-P. Rosen (rosen@adalog.fr)
Visit Adalog's web site at http://www.adalog.fr