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From: "Randy Brukardt" <randy@rrsoftware.com>
Newsgroups: comp.lang.ada
Subject: Re: Is this a bug in my code or the compiler?
Date: Sat, 13 Jun 2015 22:13:16 -0500
Organization: Jacob Sparre Andersen Research & Innovation
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Xref: news.eternal-september.org comp.lang.ada:26314
Date: 2015-06-13T22:13:16-05:00
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>David Botton" <david@botton.com> wrote in message 
>news:afb6fe82-1f67-49a8-b4b1-f814a71ba8fd@googlegroups.com...
>> That is one of the reasons why in-out's were not allowed for functions in
>> Ada 83. The code is clearly erroneous because the computation order is 
>> not
>> defined. Possibly Token_End is called before Token_Start!
>
> A programmer having to worry about order of operation in a concatenation
> operation is a language flaw in my opinion. I can accept the issue in 
> evaluation
> order of Boolean expressions or numerics (and knew of that), but not in
> non numeric types.

Yes, but at least we tried to prevent obvious cases. (It's way too late to 
change the order of evaluation rules for Ada!) And you need a lot more 
complex program to show a problem. Simple cases are illegal; we only made 
the rules apply to simple cases so that there clearly was a problem before 
the code was rejected.

                             Randy.