tonumber(), toboolean()???

[Chris Marrin <chris@...>]

Lua has a very nice tostring() function, which can use a "__tostring" 
metamethod to give string conversion support to any user defined type. 
And tonumber() exists in 5.1, but its implementation does not include a 
"__tonumber" metamethod call. It simply converts a number or string to a 
number. Everything else returns nil. So, the first question is, why not 
make the implementation of tonumber() parallel to that of tostring()?

And the related question is, why not have a toboolean() as well, with 
the same sort of __toboolean metamethod?

--
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"As a general rule,don't solve puzzles that open portals to Hell"'