Re: sunday afternoon whishlist

[Eike Decker <zet23t@...>]

2010/5/9 Florian Weimer <fw@deneb.enyo.de>:
> * Klaus Ripke:
>
>> Could x[] be syntactic sugar for x[#x+1] ?
>> It would make appending to lists so much nicer.
>
> "x[] = 5" looks about as cryptic to newcomers as "x[#x+1] = 5".  I'm
> not sure if it is an improvement.  If this operation is so common that
> it warrants its own syntax, something completely different might be
> better.  But then, "table.append(x, 5)" doesn't look too bad, either.

I don't care about beginners, but

  some_complex_name[#some_complex_name+1] = "foo"

is surely worse than

  some_complex_name[] = "foo"

not to mention

  some_function_returning_table(...)[] = "OK"

... which requires currently temporary variables.

The [] operator is maybe the one and only thing that I actually like
about PHP. It makes sense in my opinion, as it's a very common
operation when operating with stacks or queues.
It could be somewhat done right now using metatables and using a
special key, e.g.

  arr[nil] = "append"

but, a [] operator looks more useful to me than fidling around with
metatables for such a basic functionality.

Adding another thing to the wishlist: table.remove should allow a
third parameter to allow efficient table slicing, e.g.

  table.remove(arr,1,100)

instead of

  for i=1,100 do table.remove(arr,1) end

(assuming that arr is really huge)

Cheers,
Eike