Re: array index and modulo

[David Kastrup <dak@...>]

roberto@inf.puc-rio.br (Roberto Ierusalimschy) writes:

>> > There is a memory penalty. When the start index moves away from 1,
>> > Lua will stop storing these entries as array entries and start
>> > storing them as hash entries. That roughly doubles the memory used
>> > by the table.
>> 
>> [...] Still, it would appear strange that using 0 would double the
>> memory used by the table: wouldn't it be sufficient to hash just 0 and
>> use the array method for all the other consecutive entries? [...]
>
> This is what Lua does. Using 0 does not double the memory used by the
> table.

Ok, then I misunderstood that comment.

> The problem is "When the start index moves away from 1"; for
> instance, when the list elements are between 302 and 341. Then Lua
> will not keep an array with at least 341 entries to use only 40 of
> them.

Thanks.

-- 
David Kastrup, Kriemhildstr. 15, 44793 Bochum