Re: Trivial Ada question

[sjs@essex.ac.uk (Steve Sangwine)]

On Fri, 28 Jun 2002 11:54:50 +0100, Reinert Korsnes
<reinert.korsnes@chello.no> wrote:

How about:

declare
  All_OK : Boolean := True;
begin 
  for I in A'Range loop
    All_OK := All_OK and Some_Condition(I);
    exit when not All_OK;
  end loop;
  if All_OK then
    N := N + 1;
  end if;
end;

This has the benefit of being clear (almost self explanatory), but
maybe not as concise as would be liked.

Steve Sangwine

>Yes, maybe the simplest possible.
>The example below is also somehow simple,
>but I hoped for some "exit name" solution
>which I have not yet noticed :-)
>
>reinert
>
> All_OK := 1;
> for I in A'Range loop
>    if not some condition (I) then
>       All_OK := 1;
>       exit;
>    end if;
> end loop;
> N := N + All_OK;
>
>
>David C. Hoos, Sr. wrote:
>
>> How about
>> 
>> All_OK : Boolean;
>> .
>> .
>> .
>> All_OK := True;
>> for I in A'Range loop
>>    if not some condition (I) then
>>       All_OK := False;
>>       exit;
>>    end if;
>> end loop;
>> if ALL_OK then
>>   N := N + 1;
>> end if;
>> 
>> ----- Original Message -----
>> From: "Reinert Korsnes" <reinert.korsnes@chello.no>
>> Newsgroups: comp.lang.ada
>> To: <comp.lang.ada@ada.eu.org>
>> Sent: June 28, 2002 4:07 AM
>> Subject: Trivial Ada question
>> 
>> 
>>> Hi,
>>> 
>>> I would like to ask about a program construct:
>>> 
>>> I want to test if some condition holds for all values
>>> of I in A'range and in this case the variable
>>> N should be incremented by one ( N := N + 1; ).
>>> How can I do this most elegant and effective with Ada95
>>> (without "goto") ?
>>> Assume I do not want to make a separate subroutine for this.
>>> 
>>> This example is simple but not computationally optimal (two tests):
>>> 
>>>     for I in A'range loop
>>>         exit when "not some condition(I);
>>>         if I = A'last then
>>> -- Everything OK to the end:
>>>            N := N + 1;
>>>         end if;
>>>     end loop;
>>> 
>>> This example is ugly but more computationally optimal (one test):
>>> 
>>>     for I in A'range loop
>>>         if "not some condition(i)" then
>>>            N := N - 1;
>>>            exit;
>>>         end if;
>>>     end loop;
>>>     N := N + 1;
>>> 
>>> Tricks by "named loops" also seem ugly.
>>> 
>>> reinert
>>> 
>>> _______________________________________________
>>> comp.lang.ada mailing list
>>> comp.lang.ada@ada.eu.org
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>>> 
>>>