Dedicated error value/type for Lua?

[Mark Hamburg <mhamburg@...>]

Has any thought been given to introducing a dedicated error value/type for
Lua? nil also means not present in a table or no value for a variable. false
is a perfectly legitimate boolean value. The idea would be to have a single
value like nil and false that would be intended specifically for the job of
saying "an error occurred". One could also make this a type -- e.g.,
recognizing error strings as a particular type -- but that probably opens up
more cases where one would want to do things like store the value in a
table...

Mark