V: compilation error when passing option type to a function

[heronwr]

V version: V 0.1.29 9fdf04b.e250547
OS: Windows 7 Professional (x64, little-endian)
CC version: clang version 10.0.0 (https://github.com/llvm/llvm-project.git d32170dbd5b0d54436537b6b75beaf44324e0c28)

What did you do?

fn optional_arg(x ?int) {
    println("int type")

}

fn main() {
    optional_arg(1)
}

What did you expect to see?
I expected V to either to throw an error for unable to convert between any_int to option_int or convert the corresponding type to its option counterpart

What did you see instead?

C:\Users\lambda\AppData\Local\Temp\v\hello_world.1829071214341309535.tmp.c:8082:21: error: passing 'int' to parameter of incompatible type 'Option_int' (aka 'struct Option_int')
        main__optional_arg(1);
                           ^
C:\Users\lambda\AppData\Local\Temp\v\hello_world.1829071214341309535.tmp.c:8077:36: note: passing argument to parameter 'x' here
void main__optional_arg(Option_int x) {
                                   ^
9 warnings and 1 error generated.

[ntrel]

ATM V forces you to unwrap an optional produced by a function without assigning it to a variable. I think optionals should be a first class type, so your example should work too.

[heronwr]

Thanks for taking a look at this ntrel. Sorry for my ignorance, but could you elaborate on what unwrapping an optional means?

[medvednikov]

?int(1)

Yes, this example should compile.

[heronwr]

Hi Alex, I tested ?int(1) with a fresh copy of V with the latest changes from master, but it threw a bad token error

edit:
Sorry i think i misunderstood what you meant by ?int, yeah so i need a function to return an optional, something like optional_arg(option_int(1)) where option_int just returns an option int type. Thanks!

[medvednikov]

Indeed, it's not implemented. I thought it was :)

Another thing to fix.