selfhost(pyvm): MiniVmPrints – prefer JSON route early-return (ok==1) to avoid fallback loops; keep default behavior unchanged elsewhere

docs/reference/abi/NYASH_ABI_MIN_CORE.md

@@ -1,10 +1,10 @@
 # Nyash ABI Minimal Core and Evolution Strategy
 
 目的
-- 極小コアのみABI凍結し、将来拡張は交渉＋予約＋フォールバックで吸収する。
+- 極小コアのABIを長期安定化（仕様固定）し、将来拡張は交渉＋予約＋フォールバックで吸収する。
 - VM/JIT/プラグインを同じ枠組み（TypeBox + vtable + NyrtValue）に統一する。
 
-最小コア（凍結対象）
+最小コア（安定化対象）
 - NyrtValue: 16B固定 `#[repr(C)]`（`tag:u32 | reserved:u32 | payload:u64`）
 - InstanceHeader: 先頭に `vtbl:*const NyVTable, refcnt:u32, flags:u32`（実体は不透明）
 - NyMethodFn: `fn(ctx:*mut VmCtx, recv:*mut InstanceHeader, args:*const NyrtValue, argc:u32, out:*mut NyrtValue) -> NyStatus`
@@ -66,4 +66,3 @@ typedef struct NyVEntry { NyMethodSig sig; NyMethodFn fn_ptr; } NyVEntry;
 - [ ] `execute_boxcall`: vtable直行→PIC→汎用の三段整備（STRICTガード）。
 - [ ] TypeRegistry: Array/Map/String の "get/set/len" を登録→vtable優先呼び出し。
 - [ ] ABIコンプライアンステストと同一実行テストの設計をdocsに反映。
-

docs/reference/abi/nyrt_c_abi_v0.md

@@ -91,4 +91,4 @@ uint64_t nyplug_array_len(NyBox arr);
 ## 注意
 - 例外/パニックの越境は不可（戻り値/エラーコードで返す）。
 - C++ 側は必ず `extern "C"`、ELF は `visibility("default")`。
-- ABI 破壊変更は `*_v1` などの別シンボルで導入（v0は凍結）。
+- ABI 破壊変更は `*_v1` などの別シンボルで導入（v0は当面固定＝長期安定化）。

docs/reference/concurrency/semantics.md

@@ -0,0 +1,55 @@
+## Concurrency Semantics (docs-only; to guide MVP)
+
+Status: reference for userland Phase‑0. No runtime changes during the feature‑pause.
+
+### Blocking & Non-Blocking
+- `send(v)` blocks when the buffer is full (capacity reached). Unblocks when a receiver takes an item.
+- `receive()` blocks when buffer is empty. Unblocks when a sender provides an item.
+- `try_send(v) -> Bool`: returns immediately; false if full or closed.
+- `try_receive() -> (Bool, Any?)`: returns immediately; false if empty and not closed.
+- `receive_timeout(ms) -> (Bool, Any?)`: returns false on timeout.
+
+Implementation note (Phase‑0): no busy loop. Use cooperative queues; later replaced by OS-efficient wait.
+
+### Close Semantics
+- `close()` marks the channel closed. Further `send` is an error.
+- After close, `receive` continues to drain buffered items; once empty, returns a closed indicator (shape per API, e.g., `(false, End)`).
+- Double close is an error.
+
+### Select Semantics
+- `when(channel, handler)` registers selectable cases.
+- `await()` examines cases:
+  - If one or more ready: choose one (random/round‑robin) and execute its handler atomically.
+  - If none ready: Phase‑0 may block via a multi-wait helper or return false if non-blocking policy requested.
+- Fairness: no starvation requirement; Phase‑0 uses simple fairness; Phase‑2 integrates runtime help.
+
+### Structured Concurrency
+- `RoutineScopeBox` owns spawned routines.
+- On `fini()`: cancel pending children, bounded join, and ensure resource release.
+- Cancellation should unblock channel waits promptly.
+
+### Types & Safety
+- Phase‑0: runtime tag checks on `ChannelBox` send/receive are optional; document expected element type.
+- Future: `TypedChannelBox<T>` with static verification; falls back to runtime tags when needed.
+
+### Observability
+- Enable `NYASH_CONC_TRACE=1` to emit JSONL events.
+- Event schema (recommendation):
+  - Common: `ts` (ms), `op` (string), `rid` (routine id), `cid` (channel id, optional), `ok` (bool), `scope` (scope id, optional)
+  - spawn/start/join/cancel: `{op:"spawn", rid, ts}`, `{op:"join", rid, ok, ts}`
+  - send/recv: `{op:"send", cid, size, cap, ts}`, `{op:"recv", cid, size, cap, ts}`
+  - park/unpark: `{op:"park", rid, reason, ts}`, `{op:"unpark", rid, reason, ts}`
+  - select: `{op:"select", cases:n, chosen:k, ts}`
+  - close: `{op:"close", cid, ts}`
+- Causality: producers must emit before consumers observe; timestamps monotonic per process.
+
+### Test Plan (smokes)
+- ping_pong.nyash: two routines exchange N messages; assert order and count.
+- bounded_pc.nyash: producer/consumer with capacity=1..N; ensure no busy-wait and correct totals.
+- select_two.nyash: two channels; verify first-ready choice and distribution.
+- close_semantics.nyash: send after close -> error; drain -> End; double close -> error.
+- scope_cancel.nyash: RoutineScopeBox cancels children; parked receivers unblocked.
+
+### Migration Path
+- Phase‑0 userland boxes are kept while Phase‑2 runtime grows; API stable.
+- Replace cooperative wait with WaiterBox (Phase‑1) and runtime park/unpark later.

docs/reference/language/match-guards.md

@@ -1,6 +1,6 @@
 # Match Guards — Syntax and Lowering (MVP + Design Notes)
 
-Status: reference + design additions during freeze (no implementation changes)
+Status: reference + design additions during feature‑pause (no implementation changes)
 
 Scope
 - Guarded branches as a readable form of first-match selection.
@@ -37,5 +37,4 @@ Observability (design)
 - `NYASH_FLOW_TRACE=1` may trace how guard chains desugar into if/else.
 
 Notes
-- This page describes existing guard semantics and adds range/charclass as documentation-only sugar during freeze.
-
+- This page describes existing guard semantics and adds range/charclass as documentation-only sugar during the feature‑pause.

docs/reference/language/strings.md

@@ -48,7 +48,7 @@ Bytes: handled by `ByteCursorBox`.
 
 ## Proposed Convenience (design only)
 
-Parsing helpers (sugar; freeze-era design, not implemented):
+Parsing helpers (sugar; documented during feature‑pause, not implemented):
 - `toDigitOrNull(base=10) -> i64 | null`
   - Returns 0..9 when the code point is a decimal digit (or base subset), otherwise `null`.
   - CP based; delegates to `Utf8CursorBox` to read the leading code point.