Modules

Every file in the root of a folder is part of the same module. Simple programs don’t need to specify module name, in which case it defaults to ‘main’.

V is a very modular language. Creating reusable modules is encouraged and is quite easy to do. To create a new module, create a directory with your module’s name containing .v files with code:

cd ~/code/modules
mkdir mymodule
vim mymodule/myfile.v

// failcompile
// myfile.v
module mymodule
// To export a function we have to use `pub`
pub fn say_hi() {
    println('hello from mymodule!')
}

You can now use mymodule in your code:

// failcompile
import mymodule
fn main() {
    mymodule.say_hi()
}

• Module names should be short, under 10 characters.
• Module names must use snake_case.
• Circular imports are not allowed.
• You can have as many .v files in a module as you want.
• You can create modules anywhere.
• All modules are compiled statically into a single executable.

init functions

If you want a module to automatically call some setup/initialization code when it is imported, you can use a module init function:

fn init() {
    // your setup code here ...
}

The init function cannot be public - it will be called automatically. This feature is particularly useful for initializing a C library.