prometeu-runtime/docs/ARCHITECTURE.md

Prometeu Runtime — Architecture (Reset Invariants)

This document captures the high-level invariants for the reset cycle. It is a stub and will evolve as we formalize the new ISA/VM specs. The goal is to define non-negotiable properties that guide refactors without forcing legacy compatibility.

Core invariants

• Stack-based VM with heap-allocated objects.
• Garbage Collection happens at safepoints, primarily at FRAME_SYNC.
• Closures are first-class (user functions). Syscalls are callable but not first-class values.
• Coroutines are the only concurrency model.
• No backward compatibility: old bytecode formats, shims, or legacy bridges are out of scope.

Scope of this stage

• Establish tooling baselines (fmt, clippy, CI) and minimal smoke tests.
• Avoid encoding legacy ISA semantics in tests; keep tests focused on build confidence.
• Production code must remain free from test-only hooks; use dev-only utilities for determinism.

Out of scope (for now)

• Detailed ISA definition and instruction semantics beyond what is needed to compile and run smoke-level validations.
• Performance tuning or GC algorithm selection.