[Proposal] The not keyword as an alternative syntax for the logical not operator (!)

[luuhq]

Not sure if this has been brought up before, would love your thoughts on it.

Background

Many of my colleagues and I personally prefer using == false in a negative comparison instead of the bang sign !. The reason being, it's easier to spot, especially when one is debugging a live-site/SEV in the middle of the night. For example: if (!isUserAuthorized) vs if (isUserAuthorized == false).

Proposal

The proposal here is to introduce a not keyword as an alternative syntax for the unary logical not operator (!). This keyword should not require a set of parentheses after it (just like the existing ! operator). For example: if (not isUserAuthorized), which is exactly equivalent to if (!isUserAuthorized).

This syntax should also work: if (not(isUserAuthorized)).

For what it's worth, C++ also has this not keyword (among not_eq, and, and or).

[tannergooding]

There are a few existing issues. The oldest/most prevalent is probably: #27

[andrevdl]

when would uses as:

if (not(isUserAuthorized))

You could think that "not" is method defined in the same, derived or static using class.
Also can it break existed code, when somebody defined a method that is be named "not".

[AustinBryan]

For what it's worth, C++ also has this

Congrats. C++ has a lot of problems that C# doesn't have. This is a very weak argument. If you really need it just create a public static not(bool b) => !b;, but it in a static class, use a using static on every file (something you could configure VS to do for you automatically, and use it like if(not (b));.

No need for a keyword that's probably going to be in use for more pattern matching stuff when you can easily do it yourself.