Zena
On this page

Reference

This is the reference for the Zena language, its standard library, and its toolchain. It aims to be precise about what the language does today, rather than what it is planned to do.

If you're new to Zena, start with the guide instead — it introduces the same material in reading order.

How to read this reference ​

Each page covers one construct and follows the same shape: syntax, semantics, examples, and how the construct is represented in WebAssembly. The Wasm sections are there because Zena's design is inseparable from its target; if you only want to write code, they're safe to skip.

Pages are grouped by what they describe:

  • Declarations — how names are introduced
  • Types — the type system and each built-in type
  • Expressions and Control flow — how code is written and evaluated
  • Data types — records, tuples, arrays, maps, enums
  • Classes — the nominal type system, in detail
  • Libraries — modules, imports, exports, visibility
  • Standard library — one page per zena: library
  • Toolchain — the CLI, targets, flags, formatter, and language server

Conventions ​

Code samples are complete unless they end in // .... Where a sample shows an error, the offending line is commented with the diagnostic:

zena
let n: i32 = 42;
// let x: f64 = n;  // error: i32 is not assignable to f64

Grammar snippets use a light EBNF: ? for optional, * for zero or more, | for alternatives, and '…' for literal tokens.

Feature status ​

Zena is under active development. Pages carry a badge when the feature they describe isn't fully implemented:

  • Stable implemented and unlikely to change
  • In progress partly implemented; details may change
  • Planned designed, not yet implemented

Where a page has no badge, treat the behaviour as implemented but the surface as still open to change — nothing in Zena is frozen yet.