Re: Question about arrays...

[Enrico Colombini <erix@...>]

On 09/06/2013 20.10, Andrew Starks wrote:
> I know that in the current implementation, a sequence  that also contains
> hashes will still work as a sequence. That is, in my experience:
>
> T = {"at one", "at two", property = "some value"}
>
> ...works in ipairs and with the length operator. Is this behavior that is
> dependent on the implementation or is it something that is a formal part of
> Lua?

I really hope so; it would break almost all of my code in the other case.
The 5.2 manual says (3.4.6):

[[ Unless a __len metamethod is given, the length of a table t is only
   defined if the table is a sequence, that is, the set of its positive
   numeric keys is equal to {1..n} for some integer n. In that case,
   n is its length." ]]

According to this definition, the presence or absence of non-numeric 
keys should be irrelevant.
(by the way, if I remember correctly, once upon a time (Lua 4?) there 
was a magical 'n' field in arrays).

--
  Enrico