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- Subject: Re: keys in tables
- From: PA <petite.abeille@...>
- Date: Sun, 11 Dec 2005 09:54:29 +0100
On Dec 10, 2005, at 18:00, Gavin Wraith wrote:
Somebody must have asked this before! Is there anybody
who can claim to have written a Lua program that uses
a table whose keys are neither numbers nor strings,
and for which this feature is essential?
Hmmmm... not sure if it's truly "essential" as one could always devise
a string representation of any tables. Nonetheless, here is an example
of a "notification center" (e.g. a dispatch table) along the lines of
When I first learned that Lua allowed any non-nil value
as a key, I thought "Wow - democracy for table-keys".
That was quite a time ago. But what properties do we actually
require of keys in a table? 1) that keys are distinguishable,
and sometimes 2) that keys form a linear order. Can anybody
suggest any other qualities that might be desirable?
PA, Onnay Equitursay