Zeen Modules

Modules

Modules in Zeen are just source code files with a .zn extension. The name of the module is just the file name without extension (no extra declarations required).

Mostly module can look like this:

fn main() {
  let calculation = 2 + 2 * 2;

  @println("Result: {}", calculation);
}

Code separates into 3 different levels:

1. Declarations - top level code description (functions, structures, interfaces, etc.)
2. Statements - members of declarations, contains executable sequence (annotations, assigns, calls, etc.)
3. Expressions - little elements of data operating (like arithmetic, comparison, literals annotation, etc.)

We can split up our previous code with these levels:

// Declarations Level

// `main` is a function declaration
fn main() {
  // Statements Level

  // annotation statement
  let calculation = 2 + 2 * 2 /* value expression */;

  // macro call,
  // 2 expressions arguments: string literal, variable reference
  @println("Result: {}", calculation);
}

It’s highly recommended to use main.zn name for the entry file. Currently Zeen doesn’t have package manager which could automatically initialize project for you. I suggest to use next template:

• README.md
• LICENSE if necessary
• Directorydocs/

  • …
• Directorysrc/

  • main.zn

To automatically initialize all these files you can run this command inside project directory:

mkdir -p docs src
touch {README.md,LICENSE,src/main.zn}
printf '%s\n' 'fn main() {' '  @println("Hello, Zeen!");' '}' > src/main.zn