Namespaces

Each Abra file has its own namespace determined by the name of the file and its parent directories (relative to the entry point of the program).

For instance, if the entry point is main.abra and beside that main file, there is a hat.abra and a weapons/sword.abra, like so:

- main.abra
- hat.abra
- [weapons]
    - sword.abra
    - spear.abra

and if the contents of those files are as follows

// hat.abra
fn wear() {
    println("you are wearing the hat")
}

fn pull_out_rabbit() {
    println("pulled a white rabbit out of the hat")
}

// sword.abra
fn swing() {
    println("SWOOSH")
}

// halberd.abra
fn swing() {
    println("SWOOSH")
}

fn stab() {
    println("SWOOSH")
}

Then the fully qualified names of those functions would be hat.wear, weapons.sword.swing, and weapons.halberd.swing respectively.

By default, the functions in hat.abra, sword.abra, and halberd.abra are not accessible to main.abra. In order to use functions from another file, the use keyword must be used to bring them into scope.

// main.abra

use hat
use weapons/sword

wear()
swing()

By default, the use keyword makes all symbols visible. This is a convenient default, but it leads to name clashes in large projects. To avoid name clashes, users can either:

1. Use the use keyword with the except keyword to exclude an unwanted symbol

   use weapons/sword
   use weapons/halberd except swing
   
   swing()         // sword.swing
   stab()          // halberd.stab
   

2. Explicitly import individual symbols

   use weapons/sword.swing
   use weapons/halberd.stab
   
   swing()         // sword.swing
   stab()          // halberd.stab
   

   Note: multiple symbols can be imported from a namespace like this:

   use weapons/halberd.(swing,stab)
   
   swing()         // halberd.swing
   stab()          // halberd.stab