foobar:
> you raise a valid concern but this looks too complicated.
> I'd suggest to simplify into only two cases.
>
> // 1) T.INIT - as you suggested the dimension should be checked
> auto foo = new int[][](10, 20); // correct
> auto foo1 = new int[][](10); // compilation error
Keep in mind that currently this is correct and it generates a 1D dynamic array:
auto v = new int[10];
> // 2) function of the array dimension
> auto bar = new int[][](10, 20, (int x, int y) { return x*y; } );
>
> // if you want a default value just use:
> auto bar1 = new int[][](10, 20, { return 3; } );
>
> For fixed-sized arrays the function would be CTFE-able.
This is more complex than my suggestions :-)
The most common case is the initialization with a constant value. I'd like this
case to be as efficient as possible, so I don't like the { return 3; }.
The case with a more complex delegate is interesting to initialize constant
arrays:
immutable m = new int[][](10, 20, (int x, int y){ return x*y; });
But in my opinion this is not a so common operation. And it's not able to
replace Python-style array comps:
foo = [x ** x for x in lazyIterable]
So I don't like your proposals.
Maybe dsimcha will give a Phobos function to allocate & initialize a nD array
with a given const value.
Bye,
bearophile
