Functions

Functions are subprocedures that can be called multiple times. They are defined with the fnc special form.

fnc sayHello () () {
    std.println "Hello!";
};

This function can then be called with an instruction starting with that function’s name. No additional parenthesis are required.

fnc main () () {
    sayHello;
};

Functions can return values by using the ret keyword. The square function below takes a single argument of type i32 and returns a value of the same type:

fnc square (x:i32) i32 {
    ret (* x x);
};

To call this function we need to provide an argument.

    std.println (square 13);

Functions can be overloaded by other functions of the same name.

fnc square (x:u32) u32 {
    ret (* x x);
};

fnc square (x:f32) f32 {
    ret (* x x);
};

Overloaded functions must not conflict with each other, meaning they need to have different signatures. This definition would now raise errors due to conflicts:

fnc square (x:i32) i64 {
    ret (* x x);
};

Functions can be declared by omitting the function body. A declared function may be defined later in the code.

fnc square (x:f64) f64;

If you are writing a libary, there is a convention to name your functions and macros as LIBRARY_NAME.FUNCTION_NAME. If the function or macro is not intended to be called directly by your users, its name should be prepended with a minus: LIBRARY_NAME.-FUNCTION_NAME. A lot of functions and macros from base.orb don’t follow this convention for the sake of user convenience.