# PBS Specifications (Current)

This directory contains the current PBS specifications for frontend and language work.

## Authority model

- Runtime authority: `docs/specs/hardware/topics/chapter-2.md`, `chapter-3.md`, `chapter-9.md`, `chapter-12.md`, `chapter-16.md`.
- Bytecode authority: `docs/specs/bytecode/ISA_CORE.md`.
- Legacy reference only: `docs/specs/pbs_old/*`.

When a rule conflicts with runtime or bytecode authority, runtime and bytecode authority win.

## Purpose

- Define a stable syntax contract for PBS.
- Support a full frontend rewrite (lexer, parser, AST, lowering).
- Keep grammar deterministic and implementation-friendly.

## Files

- `PBS - Language Syntax Specification v0.md`: normative syntax and grammar for PBS v0 Core profile, including mandatory `mod.barrel` visibility rules.
- `PBS - Game Language Profile v1 (Draft).md`: game-first language direction for 2D workloads, defining ten normative design rules aligned with the closed VM and GC-first baseline.
- `PBS - Game Profile Syntax Specification v1 (Draft).md`: parser/lowering syntax delta for Game Profile over v0 Core (host `fn` declarations, assignment, while/break/continue, member/index postfix access).
- `PBS - Compatibility and Evolution Policy v1 (Draft).md`: compatibility contract for PBS across logical hardware updates (frozen core rules, canonical versioning, target manifests, major/minor policy, replay/conformance guarantees).