A quickie problem with an array and a right hand bracket

A quickie problem with an array and a right hand bracket

[chris.danx]

Hello everyone,

I'm trying to provide an array for quickie conversion between numbers and
character equivalents like this

    type array_16 is array (natural range 0..15) of character;

    basic_16 : constant array_16 := ('0'..'9'|'a'..'f');

The compiler corrected me on the use of a comma where the dda ("d divides a",
from math sorry, it's a bar or more symbol) but this doesn't help with
"unexpected parenthesis error" when it's compiled.  What's the problem?  It
looks correct to me but clearly i am missing something (very subtle) point.

In case i get the use text_io and tear off the start and end parts for
displaying in other bases argument.  I do not want to use text_io in this manner
since i want to remove (as much as possible) dependance on the standard packages
(for now).


Thanks,
Chris Campbell

Re: A quickie problem with an array and a right hand bracket

[Ted Dennison]

In article <eV6V6.8331$6d5.1657665@news2-win.server.ntlworld.com>, chris.danx
says...
>I'm trying to provide an array for quickie conversion between numbers and
>character equivalents like this
>
>    type array_16 is array (natural range 0..15) of character;
>
>    basic_16 : constant array_16 := ('0'..'9'|'a'..'f');

I don't think you can use the '|' character that way. I'm not sure what your
right hand side would even mean if it were valid.

Probably the easiest way to do this would be:

basic_16 : constant array_16 := "0123456789abcdef";

Of course it would be even easier to just use "String" (or a subtype thereof)
instead of making your own character array type. But you may have your reasons
for that.

---
T.E.D.    homepage   - http://www.telepath.com/dennison/Ted/TED.html
          home email - mailto:dennison@telepath.com

Re: A quickie problem with an array and a right hand bracket

[Jeffrey Carter]

"chris.danx" wrote:
> 
> Hello everyone,
> 
> I'm trying to provide an array for quickie conversion between numbers and
> character equivalents like this
> 
>     type array_16 is array (natural range 0..15) of character;
> 
>     basic_16 : constant array_16 := ('0'..'9'|'a'..'f');
> 
> The compiler corrected me on the use of a comma where the dda ("d divides a",
> from math sorry, it's a bar or more symbol) but this doesn't help with
> "unexpected parenthesis error" when it's compiled.  What's the problem?  It
> looks correct to me but clearly i am missing something (very subtle) point.

Your compiler is expecting something like

('0' .. '9' | 'a' .. 'f' => Some_Value)

so hitting that right parenthesis is throwing it off. Later it would
complain that the index type in the aggregate (characters) does not
match the index type of Array_16 (Natural range 0 .. 15), but it's not
getting to that point.

Since Array_16 is a string type, you could simply use a string literal:

Basic_16 : constant Array_16 := "0123456789abcdef";

You can also use a normal aggregate:

Basic_16 : constant Array_16 :=
   (0 => '0', 1 => '1', 2 => '2', 15 => 'f', 14 => 'e', 13 => 'd',
    3 => '3', 4 => '4', 5 => '5', 12 => 'c', 11 => 'b', 10 => 'a',
    6 => '6', 7 => '7', 8 => '8',  9 => '9');

-- 
Jeffrey Carter

Re: A quickie problem with an array and a right hand bracket

[chris.danx]

Thanks all,
Chris Campbell