V2 string

[Derek Parnell]

On Thu, 05 Jul 2007 00:15:41 -0700, Sean Kelly wrote:

> Derek Parnell wrote:
>> I'm converting Bud to compile using V2 and so far its been a very hard
>> thing to do. I'm finding that I'm now having to use '.dup' and '.idup' all
>> over the place, which is exactly what I thought would happen. Bud does a
>> lot of text manipulation so having 'string' as invariant means that calls
>> to functions that return string need to often be .dup'ed because I need to
>> assign the result to a malleable variable. 
> 
> So just use char[] instead of 'string'.  I don't plan to use the aliases 
> much either.

It's not so clear cut. Firstly, a lot of phobos routines now return
'string' results and expect 'string' inputs. Secondly, I like the idea of
general purpose functions returning 'const' data, because it helps guard
against inadvertent modifications by the calling routines. It is up to the
calling function to explicitly decide if it is going to modify returned
stuff or not.

For example, if I know that I'll not need to modify the 'fullpath' then I
might do this ...

   string fullpath;

   fullpath = CanonicalPath(shortname);


However, if I might need to update it ...

   char[] fullpath;

   fullpath = CanonicalPath(shortname).dup;
   version(Windows)
   {
      setLowerCase(fullpath);
   }

The point is that the 'CanonicalPath' function hasn't got a clue what the
calling function is intending to do with the result so it is trying to be
responsible by guarding it against mistakes by the caller.

-- 
Derek
(skype: derek.j.parnell)
Melbourne, Australia
5/07/2007 5:17:33 PM