The stately := operator feature proposal

[MrzlganeE]

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