Modules and Imports

Sysl organises code into modules. Each source file declares one module; other files import from it by path.

Module declarations

module oskit.kernel

The declared module path must match the file’s directory path. The driver validates this at compile time. Files without a module declaration are treated as anonymous and participate in no name mangling.

Imports

import posix.stdlib.{malloc, free}      // named imports
import posix.string.*                    // wildcard import
import posix.io.{open => fopen}         // aliased import

Imports are resolved through module metadata (.smeta) produced by dependent modules and merged into analysis scope.

Visibility

Declarations are public by default. Prefix a declaration with private to keep it file-local:

private myHelper() -> int = 42        // not exported
myPublicFunc() -> int = 0             // public

Name mangling

Functions and global variables defined in a module are mangled with the module path to prevent cross-module collisions:

module std.strings  → trim_space  → std_strings__trim_space
module mylib        → helper      → mylib__helper

Module parts are joined by _, separated from the symbol name by __. Source code always uses the short name; the compiler resolves it to the mangled form.

Never mangled:

• main
• extern functions
• builtin functions
• functions in files without a module declaration
• any function whose name matches an extern declaration in the current compilation

See also

• Language Reference Scope
• Type System
• Attributes and Tests
• Compiler Pipeline