Jim, VFPT can put attention on this problem.

Many VFP functions check variable type before evaluate the parameter,
but other check null before type;
this creates one remarkable amount of problems with NULL values.

An example:

? CTOBIN(.NULL.) && This return a ok NULL value

x = .NULL.
? CTOBIN(m.x)     && This return a error because x is a logical
? VAL(m.x)        && This see null, and not check the type of x

I know the reason of this,
and "I see" code C++ that the team have written.

VFPT can change the evaluation order:
To be able before estimating the type, to estimate if it is null for all VFP functions ?

Thanks