Exports

Exports define what a .si file provides to importers.

Rules

Each file may contain exactly one export statement. A second one is a parse error: Multiple export statements found.
A file with no export can still be run directly; it just has nothing to import.
Exports are either:
- Map export: export { name: expr, ... }
- Expression export: export <expr>

export {
    add: |a, b| a + b,
    PI: 3.14159,
}

This file exports a map. Importers can take the whole module (import util, then util:add(…)) or a single key (import util:add, then add(…)).

answer = 42
export answer

If this file is answer.si, then import answer binds the number 42 itself. Only map exports can be indexed with : or imported key by key.

make = || {
    return {
        inc: |x| x + 1,
        double: |x| x * 2,
    }
}

export make()

The export expression is evaluated once, when the module is first imported, and the resulting value is cached for every later import.