Re: Arithmetic on strings

[Roberto Ierusalimschy <roberto@...>]

> Concerning (2): not all types have metatables so boolean is still
> somewhat of a problem then. (I can live with it.)

We can use the metatables for strings (if at least one argument is
a string)! This already works both in 5.1 and 5.2:

mt = getmetatable("")

mt.__concat = function (a,b)
  return tostring(a) .. tostring(b)
end

print("result: " .. {})     --> result: table: 0x8172130
print(false .. " x " .. true)  --> false x true


-- Roberto