[Bug]: Differnt results from equivalent math operations

[NMMT76]

Contact Details

No response

Compiler version

v.1.18.4

What happened?

First off, thank you for ZX Basic, without it I'd never have gotten so far on my "virtual expansion device" work ( Zero-EM )

Now onto the issue. As i was writing/testing some new webcam related functions in Zero-EM i came across a strange behavior, so i dug a bit deeper.

As you can see from the example, two different results for an equivalent operation. My guess is that the - sign at the beginning of the first one forces some sort of type expansion/coercion that doesn't happen on the second.

While its easy to work around it, by only using INTEGER's or "hinting" at the need for type expansion/coercion, its still "unexpected behavior".

DIM adjbri,adjcon,adjgam as UBYTE
adjbri=99
adjcon=99
dim brires,conres as INTEGER

CLS

brires=-100+adjbri
conres=-100+adjcon
Print at 0,0;"Bri:";str(brires);" Con:";str(conres)
brires=adjbri-100
conres=adjcon-100
Print at 1,0;"Bri:";str(brires);" Con:";str(conres)

Kind regards and many thanks for your work

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