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Hi, No sure if this has already been reported as a bug.

In 1085 the following code works as expected but in 1088 it seems as if Not is no longer working correctly.

Try this: If Not (-1 = a)

It is probable that the parsing of your statement isn't working the way you expect.

In C++ (and this may apply to how the AppGameKit compiler parses), 'Not' has precedence over equality ('==' in C++ and '=' in AppGameKit Basic if statement). So your statement might be being evaluated as "(Not a) == -1".

And, just for safeness, swapping the sides on the equality test doesn't hurt.

I had a strange case in another language where the order of a constant value (like your -1) and a variable comparison worked in way and not the other.

No still does not work correctly.

As I said in 1085 this works correctly.

a > -1 fixes it for me at the moment. Maybe someone else can confirm it's as a bug !

thanks Stuart

You could also do "a <> -1". This is more of the proper reinterpretation of your original code.

This is not a bug so much as an issue of how things get parsed. The precedence of different operators (Not, And, Or, ==, <>, etc.) needs to be known if you want to write logical expressions without parenthesis.

And there isn't any documentation about the operator precedence that AppGameKit Basic uses. We cannot assume the same as C++ (MS Visual Basic does not use the same precedence as Ansi C++, for instance).

Further googling found an FE post (from the closed forum) that describes AppGameKit Basic as using BBC Basic (?). And it puts unary+- and Not as higher precedence than comparisons (<,>,<>,==,>=,<=). So your original statement was being parsed the way I suspected as: (Not a) = -1