Re: table.clear

[Ulrich Schmidt <u.sch.zw@...>]

Thats exactly why i cant see the benefit from a table.clear().

I did a small test to be sure at a point i want to speak about:

-- 8x ------------------------------------------------------------
> t1={}
> t2={}
> tx={}
> t1.a=tx
> t2.a=tx
> =tx, t1.a, t2.a
table: 0x00077698       table: 0x00077698       table: 0x00077698
>-- 8x ------------------------------------------------------------

This shows me both tables t1/t2 points to the same table tx. let's think 
about what happens if i would do a T2:clear():
In case the clear clear function wants to free all t2 entries 
immediately, the clear function needs to check double references for 
each table item of type table/function.

For me this looks like, the table.clear() needs to do the same stuff, 
the _gc normally does later in background.

table.clear() could be faster, if it does not check for double 
references but this narrows the usage of table.clear().

Ulrich.

Am 14.12.2013 07:55, schrieb Coda Highland:
> A routine using the Lua C API, no, you're right. A routine with access
> to the internals? If I'm not mistaken, it'd be fairly easy to replace
> the table contents with a fresh object and leave its children to be
> collected on the next GC sweep since they'll have become inaccessible.
>
> /s/ Adam