Metatables for functions

[Mark Hamburg <mark@...>]

Is there any reason not to support metatables for functions? Obviously  
the __call metamethod is superfluous for functions, but I could  
imagine uses for other cases. In particular, one could then consider  
using operators to combine functions. Since these cases would  
currently just end in an error or in the generic metatable for  
functions and given that functions aren't particularly tiny objects to  
begin with, the cost seems like it ought to be small.

I'll have to think about whether this would be truly useful or just  
interesting, but I was wondering whether there is a reason why it  
would be a bad idea.

Mark