Re: Checking to see if a string is a letter

[deuteros <deuteros@xrs.net>]

On Thu 05 Apr 2012 01:24:05p, Martin Dowie <martin@re.mo.ve.thedowies.com> wrote in 
news:514763028355339029.041536martin-re.mo.ve.thedowies.com@news.btinternet.com:

> deuteros <deuteros@xrs.net> wrote:
>
>> Alright, here's my function:
>> 
>>    function isVariable(token: in String) return Boolean is
>>       ParserException : Exception;
>>    begin
>>       if(token'Length = 1) then
>>          return (Is_Letter(token(1)));
>>       end if;
>> 
>>       raise ParserException with ("Not a letter : " & token);
>>      
>>    end isVariable;
>> 
>> But I'm getting this warning:
>> 
>> warning: index for "token" may assume lower bound of 1
>> warning: suggested replacement: "token'First + -1"
> 
> See http://www.ada-auth.org/standards/12rm/html/RM-3-6-3.html to see how
> String is defined.
> 
> From this you can see that token may not have a value at "token (1)",
> perhaps it is indexed by 10..20.

Yeah, I knew that much. I just didn't know how to make the compiler know
that it will always be 1. 

> NB: ParserException is declared locally, so isn't visible to any
> subprogram that could attempt to catch it...you'd need to use "when
> others =>". 

For the purposes of this particular project, the program is just supposed to abort
whenever there's an exception. Thanks though.