Can't define types inside functions

[Anthony-Gaudino]

V version: 0.1.25 87c0155
OS: Ubuntu x86_64

What did you do?
Executed this code:

fn main () {
    type Myint int
    a := Myint(100)
}

What did you expect to see?
Program executed without errors.

What did you see instead?

unexpected token: `}`
    3|     type Myint int
    4|     a := Myint(100)
    5| }

---

Fails with different error:

fn main() {
    type Myint int
    a := Myint(100)
    println(a)
}

`unresolved` needs to have method `str() string` to be printable
    3|     type Myint int
    4|     a := Myint(100)
    5|     println(a)
                    ^
    6| }

---

This works:

type Myint int                                                                   
                                                                                 
fn main() {                                                                     
    a := Myint(100)                                                              
    println(a)                                                                   
}

[Bowero]

I'm afraid there could be a lot of problems if you can define types in functions. These could overwrite each other, causing other parts of the program to stop working. I see no added value in supporting this.

[medvednikov]

Both C and Go allow this, I've never personally never used this feature.

Any thoughts on the benefits? I guess it allows to define types that are only used in the function, but you can also use unexported module level types.

[medvednikov]

One way to handle this is use anonymous functions and structs inside function bodies, and use named types at the module level.

[Anthony-Gaudino]

Rust also allows it:

fn main() {
    type MyType = u8;
    let a: MyType = 100;

    println!("{:?}", a);
}

Here's an example in Linux

[medvednikov]

It has been decided to support this :)