string types: const(char)[] and cstring

[Regan Heath]

Aarti_pl Wrote:
> Bill Baxter pisze:
> > Oskar Linde wrote:
> >> Myron Alexander skrev:
> >>> noSpam wrote:
> >>>> Walter Bright wrote:
> >>>>> Derek Parnell wrote:
> >>>>>>  const(char)[]  // A mutable array of immutable characters?
> >>>>>>  const(char[])  // An immutable array of mutable characters?
> >>>>>>  const(const(char)[]) // An immutable array of immutable characters?
> >>>>>>  char[]         // A mutable array of mutable characters?
> >>>>>>
> >>>>>> What will happen with the .reverse and .sort array properties when 
> >>>>>> used
> >>>>>> with const, invariant, and final qualifiers?
> >>>>>
> >>>>> They'll all fail.
> >>>>
> >>>> I think it's better to return reversed/sorted copy. This will make 
> >>>> such change more backward compatibile.
> >>>
> >>> This makes sense. For immutable arrays, the definition should drop 
> >>> "in place" and just return a copy.
> >>
> >> Which would be very confusing. This is instead a perfect opportunity 
> >> to  take the *much* better path of finally depreciating the .sort and 
> >> .reverse "properties". Equally good or better library implementations 
> >> are possible (and exists). For example, .sort can't take an ordering 
> >> predicate. 
> > 
> > +1 (and thanks for your predicate-accepting sort routine, Oskar!)
> 
> +1
> 
> > 
> >> Also, the special casing of reversing char[] and wchar[] arrays, 
> >> preserving the encoded unicode code points is definitely (imho) too 
> >> specialized to belong in the language (runtime) as opposed to a library.
> > 
> > No opinion there.  What about the special code-point-at-a-time foreach 
> > for char[]?  Do you dislike that too?
> > 
> 
> IMHO that should not be in language. That's why I am opting for string 
> *library* class/struct which could take care about such cases.

I agree.  I tend to think there are certain things which some apps don't need, in which case they can use the 'string' alias.  Other apps need to do this sort of thing and want a 'String' class to handle it.  I think there is room for both in the phobos/tango libraries.

The default language/library support can reverse utf8 and 16 but it's not ideal, eg.  convert to utf32, reverse, convert back. ;)

Regan