Re: Lookup nil table index

[Rici Lake <lua@...>]

On 30-Nov-06, at 10:54 AM, Javier Guerra wrote:

> anything [nil]  => nil
>
> currently both forms generate an error, and there's very little hope 
> that it
> may change.

Lua 5.1.1  Copyright (C) 1994-2006 Lua.org, PUC-Rio
> return ({})[nil]
nil

-- *Setting* generates the error:
> ({})[nil] = 42
stdin:1: table index is nil
stack traceback:
        stdin:1: in main chunk
        [C]: ?

-- But you can make a table which maps nil onto something other than 
nil:

> a = setmetatable({}, {__index=function(_, k) if k == nil then return 
42 end end})
> =a[42]
nil
> =a[nil]
42