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From: "Jeffrey R. Carter" <spam.jrcarter.not@spam.not.acm.org>
Newsgroups: comp.lang.ada
Subject: Re: Can anyone help with GNAT.Perfect_Hash_Generators ? (Possible
 memory corruption)
Date: Thu, 8 Sep 2016 23:15:41 -0700
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Xref: news.eternal-september.org comp.lang.ada:31736
Date: 2016-09-08T23:15:41-07:00
List-Id: <comp.lang.ada>

On 09/08/2016 11:04 PM, Natasha Kerensikova wrote:
> 
> On 2016-09-08, Jeffrey R. Carter <spam.jrcarter.not@spam.not.acm.org> wrote:
>>
>> Clearly it needs to have the assumption, that all Strings have a lower bound of
>> 1, eliminated.
>>
> 
> I thought it would be easier to make the assumption internally true
> instead.
> 
> Since the first thing it does with the input is to copy it internally
> using the function New_Word, I would propose a fix along the line of
> replacing it from
> 
>    function New_Word (S : String) return Word_Type is
>    begin
>       return new String'(S);
>    end New_Word;
> 
> to
> 
>    function New_Word (S : String) return Word_Type is
>       Result : Word_Type := new String (1 .. S'Length);
>    begin
>       Result.all := S;
>       return Result;
>    end New_Word;

Perhaps I should have said, "all Strings passed to it have a lower bound of 1".
Clearly it can ensure any characteristic it likes about Strings it creates. The
current approach assumes S has a lower bound of 1; your proposal does not. So I
consider your proposal as doing what I said.

Does

   return new String (1 .. S'Length)'(S);

work?

-- 
Jeff Carter
"English bed-wetting types."
Monty Python & the Holy Grail
15