main.d(61): Error: temp_[i_] isn't mutable

[Ben Hanson]

Hi Andrei,

== Quote from Andrei Alexandrescu (SeeWebsiteForEmail at erdani.org)'s article
> On 06/20/2010 12:56 PM, Ali Çehreli wrote:
> > Ben Hanson wrote:
> >> == Quote from Justin Spahr-Summers (Justin.SpahrSummers at gmail.com)'s
> >>> "string" is actually an alias for "immutable(char)[]" (and
> >> similarly for
> >>> the other string types), so its contents are not modifiable, though
> >> its
> >>> length can be adjusted and contents appended. If you need to be
> >> able to
> >>> modify the characters, just use char[] instead. You can then use the
> >>> .idup property to get a string afterward.
> >>
> >> I'm converted temp_ to CharT[] as suggested, but the conversion back
> >> to a string is failing:
> >>
> >> _charset = temp_.idup;
> >>
> >> main.d(76): Error: cannot implicitly convert expression (_adDupT((&
> >> D58TypeInfo_AT4main14__T5regexTAyaZ18basic_string_token5CharT6__initZ),cast
> >>
> >> (string)temp_)) of type immutable(CharT)[] to string
> >
> >
> > Would it work for you if the regex template took the character type
> > instead of the string type?
> >
> > The relevant lines:
> >
> > template regex(CharT)
> > {
> > // ...
> > alias CharT[] StringT;
> > StringT _charset;
> > enum size_t MAX_CHARS = CharT.max + 1;
> > // ...
> > _charset = squeeze(_charset.idup).dup;
> >
> > And then, in main:
> >
> > regex!(char).basic_string_token token_;
> >
> > Ali
> IMHO it's more general if the regexp took the string type as a
> parameter. This is because later that is easier generalizable to
> accepting a range that's different from an array.
> My dream: to have a compile-time-generated regex engine that can operate
> on any input stream.
> Andrei

I'm currently using strings for the regex strings themselves. In lexertl, I use
templated free functions what work with iterators, which means input can come
from different sources. This sounds like the kind of thing you are talking
about?

Regards,

Ben