inconsistencies between arithmetic and boolean operators

[Adrien de Croy <adrien@...>]

As work on __cast progresses, I've come across an issue relating to 
boolean operators.

Arithmetic operators attempt to convert both operands to a number first, 
so they work fine with __cast.

boolean operators insist however that the 2 operands have the same type, 
else the result is zero.  This is checked first.

This means that the following code

var1 = "3";
var2 = var1 * 2;

is valid and var2 will have the numeric value of 6

however

var1 = "3"
if(var1 < 4) then
...

is invalid, since var1 and 4 have different types, the result is an 
error.  If you wanted this to "work" you'd need to write

var1 = "3"
if((var1 * 1) < 4) then
...

the multiplication converts var1 in-place to a number.

Shouldn't the boolean operators try and do something like this?

e.g. instead of simply returning false on a type mismatch, try (e.g. by 
__cast metamethod) to demote the higher type to the lower type, where 
the precedence of types is (in descending order)

TABLE
USERVALUE
STRING
NUMBER
BOOLEAN


Adrien

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