Re: Ok - WHAT are those "Maps.Identity" things ???

["1.AAC0832" <z24ba7.net>]

On 1/5/22 8:01 AM, Jeffrey R.Carter wrote:
> On 2022-01-05 01:54, 1.AAC0831 wrote:
>>
>> The docs say to use Index(source,substr,<something>,<something-identity>)
> 
> I don't know what "docs" you mean. Anyone using Ada should be familiar 
> with its standard library, which is documented in Annex A of the ARM at
> 
> http://www.ada-auth.org/standards/aarm12_w_tc1/html/AA-A.html
> 
> (I provide the link to the AARM as the annotations are sometimes useful.)
> 
> The documentation for Ada.Strings.Fixed is at
> 
> http://www.ada-auth.org/standards/aarm12_w_tc1/html/AA-A-4-3.html
> 
> and lists 6 functions named Index (and 2 for Index_Non_Blank). Of these 
> I mostly use the one at paragraph 9:
> 
> 9  function Index (Source   : in String;
>                     Pattern  : in String;
>                     Going    : in Direction := Forward;
>                     Mapping  : in Maps.Character_Mapping
>                                  := Maps.Identity)
>        return Natural;
> 
> with the defaults for the last 2 parameters. Occasionally I've used a 
> Going => Backward,


   I'm using unbounded strings and there's a version in
   that library with the same params - but Gnat seems
   to DEMAND the last two params. Might try the fixed
   library by casting my unbounded to string ...

   Anyway, in frustration I just wrote my own. Works good
   and I was able to finish what I wanted to do.


> The Mapping/Test parameters are for specialized needs, such as 
> case-insensitive matching or folding accented characters together, and 
> the default will work if you don't need anything like that.

   I've been programming since a tad before the dawn of the
   Apples and Commodores - punch cards and serial terminals
   wired to the mini-mainframe, FORTRAN, COBOL, that horrible
   stuff. For some reason I just can't grock a lot of the Ada
   docs. Lots and lots of DESCRIPTIONS about how to do things
   but a "picture" is worth a thousand words ...

   But I really really like Pascal better.