So, I know how to determine if a form IS in a formlist:

if ref.IsInList FormList

But how do I determine that it is NOT? How do I negate boolean values? I've tried:

if !(ref.IsInList FormList)

but that's apparently invalid. I've tried searching for an answer, but I get dozens of pages of unrelated stuff.

EDIT: seems that boolean values are actually just single bit integers, meaning value is 1 or 0. So, I should do:

if 1 - (ref.IsInList FormList)

right?

Personally, I'd do
if ref.IsInList FormList == 0
in case it returns a non-zero value besides 1. Not necessarily for this case in particular, but as a negative result check to use with nearly any function.

Queue

There's no proper boolean functions per se, they just return 1 or 0 so comparing values works. Also of note, Haama (IIRC) did some pretty heavy testing and discovered it's a little more efficient to do

if(Thing)else   STUFFendif

than

if(Thing == 0)   STUFFendif

Good to know; I've been brutally optimizing my script, and will add that to the list of things to do.

I'm surprized, because the test would be the same in assembly either way; I guess to compare to 0 in this scripting language is more costly.

Edit - to elaborate:

say, in a given programming language, you put
.if x == 0
;do stuff
.endif

that would translate to
cmp x, 0
jne @endif
;do stuff
@endif:

and to compare
.if x
;do stuff
.endif

would be
cmp x, 0
je @endif
;do stuff
@endif:

So the only difference is the type of jump, but the comparison would be done the same way.

Queue

Given what was stated above, I think it's like so:

"if (x==0)" seems to be doing 2 comparisons. There's the contents, (x==0), which is itself a comparison operation. We'll call the result A. The if statement then does another comparison operation on the result: (A != 0). So, I'm thinking what actually is happening: ( ( x == 0 ) != 0 ). 2 comparison operations here rather than 1. You're right, Queue, it would be more efficient in assembly, but this is a high level language