7800basic Error

[BydoEmpire]

I ran into a recent set of changes spamming tty with this:

 please report seeing this message.
*** (497): WARNING, there seems to be a problem. your code may not run properly. please report seeing this message.
...
*** (497): WARNING, there seems to be a problem. your code may not run properly. please report seeing this message.
^C^CTerminate batch job (Y/N)? y

d:\dev\a7800\7800basic\fantasy\fantasy7800>

 

Wondering what it means, but I suppose at the very least I'm reporting seeing it.  I haven't narrowed down the cause, but I wrote a big chunk of code last night. I'm starting to selectively comment out chunks to track it down...

[BydoEmpire]

Interesting

 

Where I define all my other constants I have:

const MAP_SIZE = 8
 

This is the offending line:

    z = y*MAP_SIZE + x

 

but changing that to

    z = y*8 + x
 

fixes the problem.

Edited January 7, 2021 by BydoEmpire

[RevEng]

The warning dates back to the bB codebase, but I understand why it's showing. You're multiplying a value by a constant, and the interpreter doesn't know if it's a multiply by a power-of-two or not, so it's missing the ability to optimise the multiply.

 

For sure, just using "8" works. "def" should work too. It looks like I missed adding def to the 7800basic manual, so you can learn about it via the bB entry for it, for now.