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From: Niklas Holsti <niklas.holsti@tidorum.invalid>
Newsgroups: comp.lang.ada
Subject: Re: Null unbounded string
Date: Sat, 09 Aug 2014 23:58:10 +0300
Organization: Tidorum Ltd
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Xref: news.eternal-september.org comp.lang.ada:21630
Date: 2014-08-09T23:58:10+03:00
List-Id: <comp.lang.ada>

On 14-08-09 21:53 , Victor Porton wrote:
> Simon Wright wrote:
> 
>> Victor Porton <porton@narod.ru> writes:
>>
>>> Jeffrey Carter wrote:
>>>
>>>> On 08/09/2014 08:28 AM, Victor Porton wrote:
>>>>> Is Ada.Strings.Unbounded.Null_Unbounded_String an empty string or is it
>>>>> something different (like NULL char pointer in C)?
>>>>
>>>> It's equivalent to an empty string. How it's implemented is unimportant.
>>>
>>> But where in the ARM it's said that it is equivalent to an empty string?
>>
>> http://www.ada-auth.org/standards/12rm/html/RM-A-4-5.html#p73
> 
> It does NOT say that null string is empty string.

It says that Null_Unbounded_String represents the "null String", which
is RM-ese for a String with no elements, an empty String.

See http://www.ada-auth.org/standards/12rm/html/RM-3-6-1.html#p7 for the
definition of a "null array", and remember that String is an array type.

> Should we make a formal clarification request?

No need.

-- 
Niklas Holsti
Tidorum Ltd
niklas holsti tidorum fi
      .      @       .