Re: Lookup nil table index
[
Date Prev][
Date Next][
Thread Prev][
Thread Next]
[
Date Index]
[
Thread Index]
- Subject: Re: Lookup nil table index
- From: Rici Lake <lua@...>
- Date: 2006年11月30日 11:02:57 -0500
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