nil/None/null check

[yingshaoxo]

Describe the feature

I did a ask in golang repo, but the admin is very rude about this idea, like they never use vs-code for coding.

So I was thinking, if vlang could do the same thing, then I don't have to use golang anymore.

---

Why there doesn't have a nil check in vscode for golang?

For example, if I define a *string variable inside of a class (struct)

Whenever I use it, it will always ask coder to check and handle two different situations, one is it == nil, another is it == a string.

So that in this case, we'll never have to make mistakes with empty values. (Like getting an nil dereference error

You can have a look at flutter in vscode to see how they handle None.

---

Let me make it clear, for the following case, if we use it directly, there has high possibility it will throw errors, because text can be nil

func Test_nil(text *string) {
	println(len(*text))
}

But if the analyzer did a nil check, it will force you to write code like the following, so it will always run smoothly without error:

func Test_perfect_nil_handling(text *string) {
	if text == nil {
		// do nothing
	}
	if text != nil {
		println(len(*text))
	}
}

---

The VScode Golang Team said that they can't do it without golang language support: https://github.com/golang/vscode-go/issues/2689#issuecomment-1462792428

The golang team simply ignore questions, which shows their irresponsiblity: https://github.com/golang/go/issues/58957

Use Case

Avoid logic errors.

For example, nil dereference error.

Proposed Solution

No response

Other Information

No response

Acknowledgements

• [ ] I may be able to implement this feature request
• [ ] This feature might incur a breaking change

Version used

every version

Environment details (OS name and version, etc.)

Every platform.

[7underlines]

In V string variables are always automatically initialized with an empty string ''. So you don't have to write Test_perfect_nil_handling and can use Test_nil. In this case println(mystring.len) will output 0 if you didn't assign some value to it. The only thing that confuses me in your issue is the *. I don't know golang.

[yingshaoxo]

In V string variables are always automatically initialized with an empty string ''. So you don't have to write Test_perfect_nil_handling and can use Test_nil. In this case it println(mystring.len) will output 0 if you didn't assign some value to it. The only thing that confuses me in your issue is the *. I don't know golang.

Got it, so you are saying that Vlang doesn't have the concept of memory point?

Then how do you guys handle the null/None/nil? By using a function or type called Optional?

[ChAoSUnItY]

for any pointer types, we use stdlib function isnil to check whether a pointer is null or not, yet there's a better data representation called option, which allows checking it with even conciser syntax.

For your original question, I don't think it's a good idea since force nil check will increase code complexity (consider using if-else), plus it's not always neccesarily required to check it.