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Pawn compiler for SA-MP with bug fixes and new features - runs on Windows, Linux, macOS
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`const static` for declaring static constants #659

Closed Daniel-Cortez closed 2 years ago

Daniel-Cortez commented 3 years ago

What this PR does / why we need it:

Introduces a combination of const static for declaring constants limited to the scope of the current source file. This combination is only valid for global constants, it's not allowed for locals.

Which issue(s) this PR fixes:

Fixes #70

What kind of pull this is:

Additional Documentation:

stale[bot] commented 2 years ago

This issue has been automatically marked as stale because it has not had recent activity.

Y-Less commented 2 years ago

There area few changes I'd like to see for const static. Currently adding static changes them in to immutable variables, instead of compile-time constants. So while const can be used to declare arrays and don't get unused warnings, const static doesn't do either of those things. Which makes no sense to me.

Daniel-Cortez commented 2 years ago

Currently adding static changes them in to immutable variables, instead of compile-time constants.

If you mean changing, for example, const const_val = 0; into const static const_val = 0;, then no, it would still be a compile-time constant.

So while const can be used to declare arrays and don't get unused warnings,

Err... You mean static const can be used to declare arrays, not just const?

const static doesn't do either of those things. Which makes no sense to me.

Why would you want to define an array with a combination of keywords meant for constants only? const static is not supposed to be interchangeable with static const. Currently (and by "currently" I mean in 3.10.10, not in this PR) anything that starts with keyword const is supposed to be a compile-time constant, and I don't think changing this behavior in the compiler would be a good idea. In other words, my intention is for const static to be more of a synonym of static enum, but without the enum syntax. And I think this makes a lot of sense.

Daniel-Cortez commented 2 years ago

@Y-Less In case I got you wrong, can you give an example of how exactly you expect const static to work? Also, a small correction: at the end of my previous post I meant static enum, not const enum.

Y-Less commented 2 years ago

OK, well until you said that I didn't realise that static const and const static would be different. I'm not sure about that at all, but that doesn't mean I'm against it. I just thought this was a synonym for static const, which right now does declare an immutable variable, not a compile-time constant. But it sounds like the behaviour you're describing for const static is what I meant in the first place.

Y-Less commented 2 years ago

OK, I merged it anyway since const static was previously an error so while it might have made sense to have them mean the same thing, they didn't before.

Daniel-Cortez commented 2 years ago

OK, I merged it anyway since const static was previously an error so while it might have made sense to have them mean the same thing, they didn't before.

Yes, this was exactly my point. While const static is not synonymous to static const, it doesn't break anything. My initial intention was to implement this new combination of specifiers as static const const (see https://github.com/pawn-lang/compiler/issues/70#issuecomment-750294881), but then it didn't sound right to me with the same specifier repeating two times, as well as it didn't seem very convenient to use, because of having more characters to type, which is why I thought const static would be a much better option.