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From: "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>
Subject: Re: Usage of \ in Ada
Newsgroups: comp.lang.ada
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Date: Wed, 23 Aug 2006 22:25:39 +0200
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Date: 2006-08-23T22:25:29+02:00
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On 23 Aug 2006 10:31:25 -0700, Adam Beneschan wrote:

> Dmitry A. Kazakov wrote:
>> On 22 Aug 2006 11:13:28 -0700, Adam Beneschan wrote:
>>
>>> Dmitry A. Kazakov wrote:
>>>
>>>> P.S. it seems that OP question actually cannot be answered. Whether \ is
>>>> reserved for a control function depends on the platform.
>>>
>>> No, it depends on ISO 10646.  And character 92 (\) is not reserved for
>>> a control function in that ISO standard.  See also RM95 2.1(17).
>>
>> Yes, that should exclude the code position 16#5C# (\).
>>
>> Its wording is interesting, because it uses "code position", and yet leaves
>> source representation free. I wonder, if that might lead to confusion.
> 
> Apparently it has.  Either you're really confused, or I'm really
> confused about what you're trying to say, or possibly both.
[...]

I have already agreed that the code position 16#5C# should pose no problem. 

What I meant is a rationale behind the choice made to reference some code
positions as potentially illegal. I don't understand the reason why,
provided that the source representation is explicitly stated as irrelevant.
As an example, I gave a program in HTML or XML encoding, which
representation allows to place *any* code position into a string literal.
According to ARM this program could be illegal, without obvious reason.

In other words, how can an Ada compiler know if the code position of, say,
LF is reserved for a control function? Why should it care?

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de