hakorune/docs/private/roadmap/phases/phase-15.7/single-route-single-face.md

Phase‑15.7 — Single Route, Single Face (Collections/Plugins)

Goal

• Collapse initialization, routing, and semantics into single, well‑defined boxes.
• Remove ad‑hoc branching and duplicate init; keep Fail‑Fast and observability.

Structure (target)

• PluginBootBox: one init path (OnceLock). Config ingest → loader → providers.
• MethodRouterBox: receiver → Resolver(TypeRegistry) → Invoker(builtin/plugin).
• TypeRegistry: single source of truth for (type_id, method_id, arity) + slots.
• Core crates: hako_core_string/array/map → only place for semantics.
• HostAPIBox: reverse‑call (slot/name) with grow logic and error policy.
• EnvGateBox: HAKO_/NYASH_ aliases and truthy/values normalization.
• SpecIngestBox: nyash_box.toml/hako_box.toml ingestion facade.
• DiagnosticsBox: structured JSON logs (dev aid; filterable).
• HandleCacheBox: (type_id, instance_id) → Arc reuse for identity.

Milestones (this patch)

• Runner: remove legacy secondary plugin init; PluginBootBox is the single entry.
• Legacy VM: remove early Array.slice intercept; route through one path.
• Router: MethodRouterBox now invokes PluginBox v2 via plugin host; builtin path remains via builtin executor for now.
• Array.slice Stage‑2 kept behind env NYASH_PLUGIN_ARRAY_SLICE_HANDLE=1 (HostHandle return). Build with HAKO_EXPORT_HOST=1.

Next steps

1. Elevate Router: move builtin path to Router; interpreter calls Router only.
2. TypeRegistry: wire IDs for Builder/VM/LLVM parity; facade old registry.
3. HostAPI/EnvGate adoption: replace direct C ABI/env reads across runtime.
4. Core semantics as single truth: enforce slice/indexOf/… policies in core and reflect in docs/Builder lowering.
5. Strict plugin‑on: ensure NewBox→birth resolves providers deterministically; add re‑probe util.

Testing

• plugin‑on quick/selfhost stays green for collections; plugin‑off quick validates Extern lowering for string builtins.