Re: Empty? No. Array? No. Has? Yes.

[Sean Conner <sean@...>]

It was thus said that the Great Jay Carlson once stated:
> Let's take the following code, applied to an array-like table:
> 
>   i = #t
>   t[i] = nil
> 
> This could mean three things:
> 
>   1) Shorten t by 1 by deleting the last element of the sequence. It
>   becomes shorter.[1]
> 
>   2) Make future references to t[i] return nil; the length is not
>   important. (It's just used like a table.)
> 
>   3) Make the sequence member t[i] return nil; that is, store nil but take
>   no action on length.
> 
> Note that metatables can help for a fixed length array; __len can always
> return (say) 256, always producing behavior 3. But there can't be a
> shrinkable array.
> 
> So, for total overkill, I introduce new syntax to make intent clear:
> 
>   i = #t
>   delete t[i]

  That already exists in Lua:  table.remove().  It even allows one to remove
an arbitrary entry anywhere in the array.

  -spc