Modules

Kyna supports namespace imports and JavaScript-style named/default imports:

1// legacy namespace import (still supported)
2import "./math.kyna" as math;
3 
4// JavaScript-style named imports
5import { add, sub } from "./math.kyna";
6 
7// default export import
8import greet from "./math.kyna";
9 
10// namespace import
11import * as math from "./math.kyna";
12 
13export fn add(a: int, b: int): int { return a + b; }
14export default fn greet(name: str): str { return "hi " + name; }
15export { sub, someValue };

• one source file defines a module identity;
• export adds a declaration to the module's public table; export default marks the default export; export { a, b } re-exports named declarations;
• import "path" as name loads and caches a module, analyzes it once, then exposes only exports;
• after a successful check, a dependency writes a *.kyna.kyc stamp beside the source; the next compile skips re-checking that dependency's body when the stamp still matches file size and mtime. The entry module is always analyzed. Set KYNA_DISABLE_EXPORT_CACHE to turn this off. Class shapes still come from the parsed AST;
• JavaScript-style imports bind each imported name (or the whole namespace for import * as) to the module's exported symbols;
• resolution uses the importing file's directory first, followed by configured library roots;
• cycles are diagnosed with an import stack;
• module initialization runs once and in dependency order.

Imports must precede other top-level declarations. Only named top-level declarations can be exported. Namespace reads are live, namespace writes are forbidden, and private declarations are not visible. Resolution canonicalizes the importer-relative candidate before checking repeated --module-path roots. Cycles report the full filename chain. Dependencies initialize once in postorder.

A directory passed to ky check or ky run is a package: every *.kyna file in that folder (except *_test.kyna) shares one namespace without sibling imports. Packages nested under an internal/ directory may only be imported from the parent tree of that internal folder (diagnostic KSEM1042).

Source files may use the .kyna/.ky extension for program modules and .kyna.d/.d.ky/.ky.d for ambient type-definition files. Type-definition files contribute compile-time interfaces only and are never executed.