Hew
A statically typed language for resilient actor-based services, with supervision and protocol-aware contracts built in.
Hew is a statically typed language in which actors, supervisors, and message contracts are language constructs rather than library conventions. You declare an actor with actor and a supervisor with supervisor, and the compiler enforces the isolation and message-passing rules that go with them.
What the language provides
- Actors that own their state exclusively, with the boundaries checked at compile time
- Typed message handlers and request/reply calls
- Supervision trees with restart strategies, budgets, and time windows
- Task scopes with cooperative cancellation and predictable cleanup
- Wire types carrying schema, field tags, and compatibility checks
- Native compilation through LLVM
As of v0.5.6 the compiler, actors, supervisors, and the native pipeline run real programs end to end. Distributed actor boundaries are still landing.
The Hew project
Hew is more than the compiler:
- hew.sh — language overview, installation, documentation, examples, current status, and the engineering journal
- hew.run — browser playground with editable examples, output, files, and sharing
- Hew Studio — visual actor-system editor that generates Hew code, runs examples, and reports model issues
- HEWBOT — a programming game of more than forty levels, where the server compiles your Hew program and its output drives a small robot through a grid
Between them the language is inspectable from several directions: read it, run it, model it visually, or learn it by steering a robot into a hazard.
Why build a language
Hew borrows supervision from Erlang, compile-time rigour from Rust, and the idea from Go that concurrency belongs in the language rather than in a library. Each of those has been demonstrated separately. What I wanted to find out is how a language reads and feels when all three start from the same set of rules.