What about putting array.empty in object.d?

[Jonathan M Davis]

On Wednesday, March 21, 2012 15:54:51 Daniel Murphy wrote:
> FWIW, I would rather see `if (array)` translated to `if (array.length)` and
> this become the recomended way to check if an array is empty. Wouldn't that
> remove the dependency on std.array for most of the cases?

The problem with checking whether length == 0 is that it's inefficient for some 
containers, so it's generally good practice to use empty rather than length. 
And while length == 0 is fine for arrays, it promotes bad habits in general, so 
I'm against it and think that code should pretty much always use empty rather 
than length == 0.

if(array)

is a bit different, because you're not specifically checking the length, but

if(container)

doesn't work in the general case, and stuff like

if(array || cond)

doesn't work. So, making

if(array)

be equivalent to

if(array.length != 0)

and

if(!array.empty)

rather than

if(array !is null)

may be a good idea, but it doesn't work in the general case. In the general 
case, you're still going to have to choose between length == 0 and empty, and 
I definitely think that empty is the correct choice, because it promotes good 
habits, whereas length == 0 promotes bad habits. So, there's value in putting 
empty in _object.d regardless of what happens with if.

Now, I find that I use enough other stuff in std.array, that it always gets 
imported anyway, but I don't think that putting empty in _object.d is a bad 
idea.

- Jonathan M Davis