Re: How to determine true size of a table?

[Tyranni <tyranni@...>]

If you have control of the construction of the table, you can keep a count yourself the whole time
using techniques like this:
http://www.lua.org/pil/13.4.4.html

That example tracks all accesses, but you could easily modify it to only track non-integer inserts.



Adam D. Moss wrote:
> Matt Campbell wrote:
> 
>> The only way I know to count non-indexed values in a table is like this:
>>
>> function countFields(t)
>>  local count = 0
>>  for k, v in pairs(t) do
>>    count = count + 1
>>  end
>>  return count
>> end
>>
>> Does anyone have a better solution?
> 
> 
> The above will count all values, not just non-integer-index
> parts of the table.  The length operator will also not be
> useful where the integer-index parts of the table are
> sparse.
> 
> I guess something like this is what's wanted:
> 
>> function countFields(t)
>>  local count = 0
>>  for k, v in pairs(t) do
>>    count = count + 1
>>  end
>>  for k, v in ipairs(t) do
>>    count = count - 1
>>  end
>>  return count
>> end
> 
> (brr!!!)
> 
> --adam
>