Scripts, MSL, and 'if' condition

Gaston31

Hello,

I’m having a problem with version 3.45. I’m using MSL scripts, but there seems to be a bug on my system when I use the if condition together with trackNumber. And it’s not just trackNumber: more generally, I’m having issues with conditions and the context in which I try to use them in a script, as they seem to be abnormally ignored.

Here is a script that I use live to record free-form drum loops:

#Name RecAllLoopsDrumsTrack1
if Track Empty
Record
else
NextLoop
Record

Here, the if condition and Track Empty seem to work correctly.

But when I add a condition so that the command should only work when Track 1 is selected:

#Name RecAllLoopsDrumsTrack1
if trackNumber == 1
if Track Empty
Record
else
NextLoop
Record

The condition has no effect. Even when another track is active, I can still trigger the command.

However, if I type:

Print trackNumber

in the console, I get the correct track number.

On that same console, if I enter:

#Test
if trackNumber == 1
Print "TRUE"
else
Print "FALSE"

I get FALSE every time.

And if I use:

if 1 == 1
Print "TRUE"
else
Print "FALSE"

I still get:

FALSE

Same thing.

Isn’t that strange?

There must be something I’m missing. Maybe I haven’t understood something essential about how conditions work in MSL, or about the context in which they are evaluated.

Could someone explain what is happening here?

Thanks for your help!

jeff

Re: "if Track Empty"

What comes after the "if" is called an expression that evaluates to either true or false. The words "Track Empty" is not a valid expression so that will always be false. To test if a track is empty you would write:

if loopFrames == 0

loopFrames is a variable that contains the length of the loop. The word frames can be thought of as the same as samples, though technically a frame is a collection of samples, one for each channel. Since Mobius currently can operate only in stereo, a frame is always two samples. A frame is the smallest unit of audio that Mobius uses, so if a loop has zero frames, it is empty.

Your tests with "if 1 == 1" are concerning and it shouldn't work that way. I'll have a look.

jeff

You shouldn't have to do this, but try writing it this way with parenthesis:

if (1 == 1)

If that works then there is a bug in the parser, parenthesis to surround the expression are supposed to be optional.