Re: xor

[Niklas Holsti <niklas.holsti@tidorum.invalid>]

On 12-03-28 18:23 , Michael Moeller wrote:
>
>
> On Wed, 28 Mar 2012, Georg Bauhaus wrote:
>
>> On 28.03.12 14:18, Michael Moeller wrote:
>>
>>> While this example compiles without complaints it
>>> doesn't work with procedures declared in my package. How can I
>>> make Sequential_IO visible there?
>>
>> Instantiate Sequential_IO where you need it:

   [snip solution using packages and "with"]

>>> Its a little strange, though, how dead easy coding concurrency
>>> on a Sun machine was recently while I'm not able to write out
>>> some silly bytes using the very same language.
>>
>> This is not unusual, I think, insofar as virtually every language
>> requires some effort when I/O is more than "print". Python,
>> Java, Ada, C, C++, they all have some frowned upon simple I/O procedures,
>> and then the real thing. The latter takes time getting used to.
   [snip]
> Thanks again for your quick and competent answers. This works.
>
> I agree with you on I/O. I've seen many languages and most often
> I/O is pretty peculiar.

But, from the solution that Georg gave you, it seems that your 
difficulty was not about I/O in Ada, but about the Ada package concept, 
context clauses ("with"), and perhaps generics, none of which are 
specifically related to I/O, and all of which you need to know anyway, 
in order to be productive in Ada.

> I don't want to push your helpfulness to far, but I still don't
> know whether there is any means to determine the size of a file
> from within Ada other than using a C subroutine calling fstat.

Two ways:

- Ada.Directories.Size, given the file name.
- Ada.Direct_IO.Size, given an open (Direct_IO) file.

-- 
Niklas Holsti
Tidorum Ltd
niklas holsti tidorum fi
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