Re: Question on bounded / unbounded strings

[John Smith <yoursurrogategod@gmail.com>]

On Tuesday, September 13, 2016 at 5:05:33 AM UTC-4, Dmitry A. Kazakov wrote:
> On 13/09/2016 10:46, Arie van Wingerden wrote:
> > Hi,
> >
> > for a long time I've been interested in Ada but hadn't played with it.
> >
> > Now I bit the bullet and I am trying to create a small (Windows) program
> > that:
> > 1) reads a string from STDIN (yet to do)
> > 2) fetches the contents of the PATH environment variable (done)
> > 3) splits that content in individual paths (???)
> > 4) tries to match the inputted string with part of each path (to do)
> > 5) outputs only the matched paths (to do)
> >
> > I found out the hard way that Ada is very strict about bounded versus
> > unbounded strings.
> > So I had to convert the output of 2) to an unbounded string, because I
> > could not know it's length in advance.
> >
> > Now I am a bit stuck splitting the string of paths;
> > I use GNAT.String_Split.Create, but it needs a (bounded) String as input.
> > However, I only have an unbounded string.
> >
> > QUESTION: How can I convert an unbounded string to a standard (bounded)
> > string?
> 
> Don't use either. For the thing you described (and for almost all cases) 
> standard String is a better, easier and safer choice. Bounded strings 
> are useless altogether. Unbounded string have very limited use.
> 
> P.S. Splitting/tokenization is just a wrong pattern for string 
> processing. You need not split strings at all. You just scan the string 
> from delimiter to delimiter marking beginning and end of the token and 
> then pass the substring further, e.g. building an ordered set of 
> [normalized] paths or directly matching them as they appear. It is 
> simpler, cleaner, safer and far more effective.
> 
> -- 
> Regards,
> Dmitry A. Kazakov
> http://www.dmitry-kazakov.de

Why would you say this?  I've found the ease with which you can append or manipulate unbounded strings to be very convenient.  Furthermore, I don't need to worry about computing the bound of my string.

From my experience unbounded string are very easy to work with.

But I genuinely am curious about your view on this and why.