Re: pairs(t, skey) and ipairs(t, skey)

[Coda Highland <chighland@...>]

On Wed, Oct 2, 2013 at 2:27 PM, Luiz Henrique de Figueiredo
<lhf@tecgraf.puc-rio.br> wrote:
>> Another habit we should not be practicing is thinking of Lua tables as having
>> array and hash parts.
>
> Exactly. This is an implementation detail for getting performance and reduced
> memory usage but Lua tables remain what they are: associative arrays.
>
> You don't even need to use #t if you keep track of how many items t has
> in some other way.

In a more generic sense, I have to ask: Is there a specific reason why
there isn't a way to determine how many keys are in a table at all?
Equivalently, why isn't there a way to know in advance how many
results pairs() will return?

/s/ Adam