Use the newly introduced is not operator

[0stam]

Use the newly introduced is not operator instead of not (...) is.

Running the following regular expression: (^|\`\`)\s*(if|while|.*=)(.)* not (|.* )is I have found only one occurrence of the outdated code in the entire documentation.

[Mickeon]

I wonder if there's any not (...) is in the class reference, too...

In any case, it's an innocent addition. Although, the simplification is... simpler, yeah, but may serve a different purpose. Assignments to variables and early returns like the code snippet above are pretty nifty.

[0stam]

I wonder if there's any not (...) is in the class reference, too...

After all the searching, I have read the documentation guidelines. It turns out that, to make everything more concise, you should avoid using typed code. So it makes sense that the operator is not used outside of the typing tutorial, and I don't expect to find it in the class reference.

At first I wanted to replace the operator in the expression, but then realised that this page also introduces the is operator itself, and introducing both at the same time could be misleading to someone.

[tetrapod00]

Another PR, #10085, also tries to document is not in this section (though that PR only replaces the existing usage). One of these two PRs should be accepted.

[tetrapod00]

Suggested change

	You can also simplify the expression using the ``is not`` operator::
	if body is not PlayerController:
	push_error("Bug: body is not PlayerController")
	You can also simplify the expression using the ``is not`` operator::
	if body is not PlayerController:
	push_error("Bug: body is not PlayerController")

This needs to be indented one level deeper, so it appears in the note block, since it is conceptually related to the earlier example.

You should also relocate this new is not example to after the initial is example and before the assert() example. Note that you'll have to adjust the existing or ``assert()`` statement:: line to make sense.

[0stam]

Thanks for the review, I have applied all the feedback. I have also replaced an incorrectly used "expression".

We don't have a separate documentation for the is keyword, so I would personally stick with explaining the basic version before introducing is not, but I'm no expert on the topic.

The other PR also suggest removing parentheses from if not (body is PlayerController):. It's technically correct, because is has a higher precedence than not, but it's not a very common knowledge (at least I had to check it) and I believe it's much easier to understand in the current version, especially if you see it for the first time.

[tetrapod00]

Looks good now. This PR is a better way to document is not than the alternate PR #10085.

Keeping the existing parentheses in the if not (body is PlayerController): line makes sense to me, since it increases clarity if you don't know all the precedence rules. But I'm not an expert on the GDScript style standards we use for docs examples.

[mhilbrunner]

Merged. Thanks and congrats on your first merged contribution! Sorry this one took a bit :)

[0stam]

Thank you too. I'm glad I could help :)