mutability of Lua types

[Asko Kauppi <askok@...>]

Lua numbers and strings are not mutable. Is the reason for this  
mainly the hash table usage (= changing the value would require a  
different hash slot) or are there other reasons as well?

Asking because I'd like the enum values to _be_ mutable; in such  
cases, if I base hashing solely on the 'family' of the enums, not the  
value, the value could change?

-asko