A ping for __tonumber

[Andrew Starks <andrew.starks@...>]

I've gone over the archives and read past posts on the __tonumber
metamethod idea. In light of work on 5.3, I wanted to throw out that
__tonumber would be welcomed.

Within my own Lua code, I often want to turn an object into a plain
number. The meta-methods can effectively do most of what I want, but
not when I'm dealing with relational operators when one side of is an
actual number.

`tonumber` might be more appropriate than going through the work of
defining every arithmetic metamethod that I may or may not need for
that object (it's tedious).

Finally, __tonumber just feels... missing. I even had to triple check
that it wasn't in 5.2, lest I embarrass myself. :)

Of course, I'm happy to monkeypatch tonumber (and may apply the power
patch that I found in my research). My opinion is that it would be
generally helpful, especially when/if coercion of strings to numbers
should go away[1].

-Andrew

[1]I'm in the habit of calling tonumber whenever I need a number, in
case I get a string. I use it as a silent protest that Lua coerces
strings without me asking.