Query about user data equality.

["Paul Winwood"<Paul_Winwood@...>]

I am using Lua 4.0
>From the previous reply to a query from myself by lhf I have implemented 
what I called 'deferred evaluation'  for my user data objects. 
This 'deferred evaluation' technique uses all the tag 
methods to implement my user data as a full Lua object. This all works 
excellently with one exception. The exception is that there is no tag method 
call for equality testing (when compared with the 'lt' tag method) when 
comparing a table or user data agains another type.

Would it be a good idea to add an 'eq' (or similar) tag method to allow such 
equality testing ? I can of course ask my users to work around this by 
say adding a constant to the user data item (hence invoking the 'add' 
tagmethod) before calling the equality operator but this seems somewhat 
of a hack. I think doing this would make the mapping between external 
boolean types and 'nil' much easier.

I have noticed that in the function luaO_equalObj() which is called by the 
OP_JMPNE and OP_JMPEQ opcodes. Would this be a suitable place to 
insert such a tag method call?

Paul.