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From: Gary Scott <Gary.L.Scott@lmtas.lmco.com>
Subject: Re: How to make like Fortran "do i = 1,20,2"
Date: 2000/07/27
Message-ID: <39805669.3E7CF6CF@lmtas.lmco.com>#1/1
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References: <8lpcbe$40n$1@news.uit.no> <T47$ewqox+R8@eisner.decus.org>
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Newsgroups: comp.lang.ada
Date: 2000-07-27T00:00:00+00:00
List-Id: <comp.lang.ada>

Hmmm, these and similar examples posted do not make Ada look very
elegant...it makes a very simple concept seem somewhat convoluted.

Larry Kilgallen wrote:
> 
> In article <8lpcbe$40n$1@news.uit.no>, reinert@ola.npolar.no (Reinert Korsnes) writes:
> >
> > Hi,
> >
> > How can one in Ada elegantly make a loop through each 2 element of an array ?
> > I am looking for something like: "do i = 1,20,2" in Fortran, or
> >
> > for I in A'range ("step 2") loop
> >    something...
> > end loop;
> 
> ===========
> 
> for I in A'range loop
>     if (I - A'first) mod 2 = 0
>     then
>         null;
>     end if;
> end loop;
> 
> But of course that does nothing to ensure that A'length is an even number.
> 
> ===========
> 
> for I2 in A'first/2 .. A'last/2 loop
>     declare
>         I : INTEGER := I2*2;
>     begin
>         null;
>     end;
> end loop;
> 
> That approach will have problems if either A'length is an odd
> number or if either limit of A'range is an odd number.
> 
> ===========
> 
> But what does Fortran do in those negative and odd number cases ?