On Thursday, 30 May 2013 at 00:20:00 UTC, MrzlganeE wrote:
Hi,
Please consider a request for just one piece of syntax sugar in
D.
In places where I write a bunch of short mathy code, I do not
want to use 'auto'. The := operator would allow to declare a
variable, deduce its type, and define its value.
void main() {
x := 1;
y := 2.0;
z := x * y;
y = 3.0;
}
I do not want to see the word 'auto', because it has little to
do with the problem I am expressing. I find it distracting.
'auto' suggests D's type system -- but I am just thinking of
the algorithm. I want to see less words about the type system,
and focus my eyes on the problem that I am solving.
I realize that D is not about syntax sugar, but this is
different:
- It is easily understood by computer scientists, and
mathematicians coming from many different backgrounds -- it's
not obscure like a perl syntax construct.
- I would not write 'auto' while expressing an algorithm on a
whiteboard. But I may very well write :=
- It has a historical record of use in old BNF-grammar
languages.
- I think people would really *use* it, where they don't want
to use auto today.
- It's not 'un-C-like' -- it is only not-like-C, because C
didn't support the feature. It is actually a natural fit!
for (i := 0; i < 24; i++) {
}
- It is very easily remembered: If you've seen it once, you
know it.
Today, I would rather write 'double y = 2.0;' than 'auto y =
2.0;'
But := would change that.
Please consider it.
- MrzlganeE
You can do this:
template Math(string code) {
enum Math = transform(code); // Do whatever CTFE transforms
you want
}
mixin Math!q{
x := 1;
y := 2;
writeln(x*y);
};
Although it will be a lot easier when std.regex works at compile
time...
