Re: equals metamethod and hash functions

[Rici Lake <lua@...>]

On 8-Jun-05, at 6:05 PM, Dave Dodge wrote:

> On Tue, Jun 07, 2005 at 06:27:35PM -0400, Paul Chiusano wrote:
> > In order for this to work, I need equal objects (according to __eq)
> > to hash to the same location in the table.
>
> If these objects are strictly tables, tostring() might be sufficient
> for this already.

If the objects are all unique, you can just use them as keys. No 
conversion necessary.

I think the issue here is that he wants to create equivalence classes 
of objects.

By the way, it would be a Really Bad Idea to use tostring(t) instead of 
just using t. tostring(t) is not going to keep t from being garbage 
collected, and if it were, some other object might end up with the same 
tostring() value. At any rate, it is completely unnecessary, since in 
Lua a key can be any Lua value aside from nil and NaN.

R.