== Quote from Andrei Alexandrescu (seewebsiteforem...@erdani.org)'s article
> dsimcha wrote:
> > == Quote from Max Samukha (samu...@voliacable.com.removethis)'s article
> >> On Tue, 20 Jan 2009 12:23:58 +0300, "Denis Koroskin"
> >> <2kor...@gmail.com> wrote:
> >>> One nice thing that opApply capable of is it can avoid heap activity by
> > stack-allocating data during iteration.
> >>> For example, given an array of ints, iterate over string representations
> >>> of
them:
> >>>
> >>> struct IntegersAsString
> >>> {
> >>> void opAplly(int delegate(string s) dg)
> >>> {
> >>> char[16] temp;
> >>>
> >>> foreach (i; array) {
> >>> int len = sprintf(temp, "%d", i);
> >>> int result = dg(temp[0..len]);
> >>> if (result != 0) {
> >>> return result;
> >>> }
> >>> }
> >>>
> >>> return 0;
> >>> }
> >>>
> >>> private int[] array;
> >>> }
> >>>
> >>> int array = [1, 1, 2, 3, 5, 8, 13];
> >>>
> >>> // no heap allocation take place
> >>> foreach (string s; IntegersAsString(array)) {
> >>> writeln(s);
> >>> }
> >>>
> >>> How would you do that with ranges?
> >> struct IntegersAsString
> >> {
> >> private
> >> {
> >> int[] array;
> >> char[16] temp;
> >> }
> >> char[] head()
> >> {
> >> int len = sprintf(temp.ptr, "%d", array[0]);
> >> return temp[0..len];
> >> }
> >> void next()
> >> {
> >> array = array[1..$];
> >> }
> >> bool empty()
> >> {
> >> return array.length == 0;
> >> }
> >> }
> >> void main()
> >> {
> >> int[] array = [1, 1, 2, 3, 5, 8, 13];
> >> // no heap allocation take place
> >> foreach (char[] s; IntegersAsString(array))
> >> writefln(s);
> >> }
> >
> > Yet another argument for some kind of opRange to syntactically sugar this
> > up.
> Where would that be useful in this example?
> Andrei
foreach(char[] s; array) vs.
foreach(char[] s; IntegersAsString(array))
I think a lot of stuff is going to need some kind of extra struct like this to
make it work. When this is the case, it needs to be possible to have a default
iteration method that "just works." The opDot overload, I guess, could do this,
but it's a rather blunt tool, since then you can't use opDot for other stuff and
you'd have to forward _everything_ to the opDot object.
