ASTREUM LANGUAGE

A stack-based language built on Expressions

Postfix evaluation over a simple data model of links, symbols, numbers, byte strings, and strings. Includes built-in concurrency with actors.

READ THE SPEC

WHAT IT IS

Small, explicit, and content-addressed

A postfix language built around a stack-based virtual machine, built-in operators, and a content-addressed expression model. Designed for transparency, auditability, and deterministic execution in smart contracts and off-chain tooling.

Smart contracts

Metered execution with a clear stack model, content-addressed expressions, and explicit module boundaries keeps contract logic transparent and verifiable.

General applications

Write scripts, services, and tooling where clarity, composability, and content-based addressing matter — without sacrificing ergonomics.

Concurrent actors

Built-in actor model with message passing: spawn lightweight threads, send and receive over named mailboxes, all within the same expression evaluator.

FEATURE SUMMARY

Current version: experimental / early

Stack-based evaluation with postfix operator dispatch, a ' special form, and a quote stack operator.
Six expression types: Link, Symbol, Bytes, Int, Float, and String — all content-addressed via Blake3.
Built-in operators covering unified arithmetic (+, -, *, /, %, sqrt), bitwise logic, shifts/rotates, stack manipulation (dip, drop, dup, swap), expression construction (link, head, tail, is_atom, is_eq, symbol, str, int, float, bytes), control flow (if, fn, lambda), and actor model (spawn, send, receive).
Content-addressed storage model with hash pointers (head_hash/tail_hash) for DAG-based expression graphs, runtime hash resolution via ref/load, and binary serialization via to_bytes/from_bytes.
Module system with file imports, reference imports, prefix-qualified namespaces, and circular-import protection.
Metered execution (Meter/MeterExceededError) with size-based costing per operation.
Deterministic execution mode that disables spawn, send, receive, and eval for reproducible evaluation.
Lexical scoping via Env with a def_target indirection for hygienic bindings.

LINKS

Explore the language

Syntax, operators, and the evaluation model.

Language Specification

Install the CLI, write your first file, and run it.

Getting Started

Walk through core concepts with runnable examples.

Language Tour

EBNF grammar, complete operator table, CLI flags, and reserved words.

Language Reference