On Friday, October 05, 2012 02:08:14 bearophile wrote:
> Tommi:
> > Maybe we forget about commas then, and extend if-clauses so
> > that you can properly define variables at the beginning of it.
> > Separated by semicolons.
>
> Regarding definition of variables in D language constructs, there
> is one situation where sometimes I find D not handy. This code
> can't work:
>
> do {
> const x = ...;
> } while (predicate(x));
>
>
> You need to use:
>
> T x;
> do {
> x = ...;
> } while (predicate(x));
Yeah. That comes from C/C++ (and is the same in Java and C#, I believe). I
don't know why it works that way. It's definitely annoying.
Of course, changing it at this point would change the semantics in a
potentially code-breaking manner in that if the condition relies on any
variables local to the loop having been destroyed, then its behavior will
change. That's probably an insanely uncommon situation though - enough so that
I'd be all for changing the semantics to have the scope exited _after_ the
test is done (assuming that there's not a solid technical reason to keep it
as-is). But I have no idea how possible it is to talk Walter into that sort of
change.
- Jonathan M Davis
