Re: documentation: metatable is a reference (refman is unclear)

[Coda Highland <chighland@...>]

On Mon, May 8, 2017 at 3:40 PM, Gé Weijers <ge@weijers.org> wrote:
>
>
> On Mon, May 8, 2017 at 3:02 PM, Ross Berteig <ross@cheshireeng.com> wrote:
>>
>>
>> The fact that tables are "stored by reference" is just an implementation
>> detail that makes the value semantics of tables practical to implement. This
>> is similar to strings being internalized, which is also just an
>> implementation detail that make their value semantics practical to
>> implement.
>>
>
> Lua tables do not have value semantics, as you examples are clearly showing.
>
> a={}
> b=a
> a.x = 1
> b.x = 2
> print(a.x) -- prints 2
>
> This is reference semantics. You'd see '1' if Lua implemented value
> semantics.
>
> String internalization is a different beast, because strings are immutable,
> so value semantics and reference semantics are indistinguishable if you
> ignore memory and complexity issues.
>
>
> --
> --
> Gé

In the context, I understood that what he meant was "the semantics of
a table", not "tables have value semantics".

Yes, there is a semantic difference, and he was incorrect due to his
choice of words, but the actual reasoning is sound.

/s/ Adam