hakorune/docs/reference/language/using.md

using — Imports and Namespaces (Phase 15+)

実装状況: Phase 15.5後に本格実装予定 | 基本ドット記法は実装済み

Status: Accepted (Runner‑side resolution). Selfhost parser accepts using as no‑op and attaches meta.usings for future use.

🎯 設計思想：Everything has Namespace

核心コンセプト

すべてのBox、関数、メンバーが明確な名前空間を持ち、衝突・曖昧性を根本解決。

// ✅ 実装済み：ドット記法
network.HttpClient()         // プラグイン修飾名
plugin.network.HttpClient() // フルパス

// 🚧 Phase 15.5後：明示的スコープ演算子
::print("global")           // グローバルスコープ
builtin::StringBox("test")  // 内蔵版明示
plugin::StringBox("test")   // プラグイン版明示

MIR Callee革新との統合

MIR Callee革新設計と完全統合：

// Phase 1: 型安全関数呼び出し（実装済み）
pub enum Callee {
    Global(String),          // ::print, global::func
    Method { box_name, method, receiver }, // obj.method()
    Extern(String),          // nyash.console.log
    Value(ValueId),          // 第一級関数
}

// Phase 3: 完全修飾名対応（Phase 15.5後）
pub enum QualifiedCallee {
    Qualified { namespace: Vec<String>, name: String },
    Scoped { scope: ScopeKind, name: String },
}

📊 実装状況

✅ 現在実装済み

• ドット記法: plugin.BoxName、namespace.member
• using基本構文: ファイルトップでの宣言
• エイリアス: using long.path as Alias
• プラグイン修飾: network.HttpClient

🚧 Phase 15.5後実装予定

• built-in namespace: builtin.StringBox vs plugin.StringBox
• 完全修飾名: nyash.builtin.print、std.console.log
• スコープ演算子: ::global_func、Type::static_method
• 厳密解決: コンパイル時名前空間検証

Policy

• Accept using lines at the top of the file to declare module namespaces or file imports.
• Resolution is performed by the Rust Runner when NYASH_ENABLE_USING=1.
  • Runner strips using lines from the source before parsing/execution.
  • Registers modules into an internal registry for path/namespace hints.
• Selfhost compiler (Ny→JSON v0) collects using lines and emits meta.usings when present. The bridge currently ignores this meta field.

Namespace Resolution (Runner‑side)

• Goal: keep IR/VM/JIT untouched. All resolution happens in Runner/Registry.
• Default search order (3 stages, deterministic):
  1. Local/Core Boxes (nyrt)
  2. Aliases (nyash.toml [imports] / needs … as …)
  3. Plugins (short name if unique, otherwise qualified pluginName.BoxName)
• On ambiguity: error with candidates and remediation (qualify or define alias).
• Modes:
  • Relaxed (default): short names allowed when unique。
  • Strict: plugin短名にprefix必須（env NYASH_PLUGIN_REQUIRE_PREFIX=1 または nyash.toml [plugins] require_prefix=true）。
• Aliases:
  • nyash.toml [imports] HttpClient = "network.HttpClient"
  • needs sugar: needs plugin.network.HttpClient as HttpClient (file‑scoped alias)

Plugins

• Unified namespace with Boxes. Prefer short names when unique.
• Qualified form: network.HttpClient
• Per‑plugin control (nyash.toml): prefix, require_prefix, expose_short_names
  • 現状は設定の読み取りのみ（導線）。挙動への反映は段階的に実施予定。

needs sugar (optional)

• Treated as a synonym to using on the Runner side; registers aliases only.
• Examples: needs utils.StringHelper, needs plugin.network.HttpClient as HttpClient, needs plugin.network.*

nyash.toml — Unified Using (Phase 15)

Using resolution is centralized under the [using] table. Three forms are supported:

• [using.paths] — additional search roots for path lookups
  • Example: paths = ["apps", "lib", "."]
• [using.<name>] — named packages (file or directory)
  • Keys: path = "lib/math_utils/", optional main = "math_utils.nyash"
  • Optional kind = "dylib" with bid = "MathBox" for plug‑ins (dev only)
• [using.aliases] — alias mapping from short name to a package name
  • Example: aliases.json = "json_native"

Notes

• Aliases are fully resolved: using json first rewrites to json_native, then resolves to a concrete path via [using.json_native].
• include is deprecated. Use using "./path/to/file.nyash" as Name instead.

Dylib autoload (dev guard)

• Enable autoload during using resolution: set env NYASH_USING_DYLIB_AUTOLOAD=1.
• Resolution returns a token dylib:<path>; when autoload is on, Runner calls the plugin host to load_library_direct(lib_name, path, boxes).
• boxes is taken from [using.<name>].bid if present; otherwise the loader falls back to plugin‑embedded TypeBox metadata.
• Safety: keep OFF by default. Prefer configuring libraries under nyash.toml for production.

Index and Cache (Runner)

• BoxIndex（グローバル）：プラグインBox一覧とaliasesを集約し、Runner起動時（plugins init後）に構築・更新。
  • aliases: HashMap<String,String>（nyash.toml [aliases] と env NYASH_ALIASES）
  • plugin_boxes: HashSet<String>（読み取り専用）
• 解決キャッシュ：グローバルの小さなキャッシュで同一キーの再解決を回避（キー: tgt|base|strict|paths）。
• トレース：NYASH_RESOLVE_TRACE=1 で解決手順やキャッシュヒット、未解決候補を出力。

Syntax

• Namespace: using core.std or using core.std as Std
• File path: using "apps/examples/string_p0.nyash" as Strings
• Relative path is allowed; absolute paths are discouraged.

Style

• Place all using lines at the top of the file, before any code.
• One using per line; avoid trailing semicolons. Newline separation is preferred.
• Order: sort alphabetically by target. Group namespaces before file paths.
• Prefer an explicit alias (as ...) when the target is long. Suggested alias style is PascalCase (e.g., Std, Json, UI).

Examples

using core.std as Std
using "apps/examples/string_p0.nyash" as Strings

static box Main {
  main(args) {
    local console = new ConsoleBox()
    console.println("hello")
    return 0
  }
}

nyash.toml examples

[using]
paths = ["apps", "lib", "."]

[using.json_native]
path = "apps/lib/json_native/"
main = "parser.nyash"

[using.aliases]
json = "json_native"

# Dylib (dev)
[using.math_plugin]
kind = "dylib"
path = "plugins/math/libmath.so"
bid = "MathBox"

Qualified/Plugins/Aliases examples

# nyash.toml
[plugins.network]
path = "plugins/network.so"
prefix = "network"
require_prefix = false

[imports]
HttpClient = "network.HttpClient"

# code
needs plugin.network.HttpClient as HttpClient

static box Main {
  main(args) {
    let a = new HttpClient()         # alias
    let b = new network.HttpClient() # qualified
  }
}

Runner Configuration

• Enable using pre‑processing: NYASH_ENABLE_USING=1
• CLI from-the-top registration: --using "ns as Alias" or --using '"apps/foo.nyash" as Foo' (repeatable)
• Strict mode (plugin prefix required): NYASH_PLUGIN_REQUIRE_PREFIX=1 または nyash.toml の [plugins] require_prefix=true
• Aliases from env: NYASH_ALIASES="Foo=apps/foo/main.nyash,Bar=lib/bar.nyash"
• Additional search paths: NYASH_USING_PATH="apps:lib:."
• Selfhost pipeline keeps child stdout quiet and extracts JSON only: NYASH_JSON_ONLY=1 (set by Runner automatically for child)
• Selfhost emits meta.usings automatically when present; no additional flags required.

🔗 関連ドキュメント

設計・アーキテクチャ

• MIR Callee革新設計 - 型安全関数呼び出し
• Phase 15.5 Core Box統一 - プラグイン統一計画
• Box Factory設計 - builtin vs plugin優先順位

実装ガイド

• Callee実装ロードマップ
• プラグインシステム - プラグイン開発ガイド
• 完全言語リファレンス - 全構文仕様

📝 実装ノート

Notes

• Phase 15 keeps resolution in the Runner to minimize parser complexity. Future phases may leverage meta.usings for compiler decisions.
• Unknown fields in the top‑level JSON (like meta) are ignored by the current bridge.
• 未解決時（非strict）は実行を継続し、NYASH_RESOLVE_TRACE=1 で候補を提示。strict時はエラーで候補を表示。
• Phase 15.5完了により、現代的な名前空間システムを実現予定

Include/Export (Phase 1)

Simple include expression for file‑scoped modules（Phase 1 提案）。将来は using/Runner 解決へ統合予定。

Overview

• One file exports one static box. include(path) evaluates the file and returns that Box instance.

Syntax

local Math = include "lib/math.nyash"
local r = Math.add(1, 2)

Rules

• Single static box per file（0/複数はエラー）
• Expression form: include(...) は Box インスタンスを返す式
• Caching: 同一パスは一度だけ評価（2回目以降はキャッシュ返却）
• Path resolution（MVP）:
  • Relative allowed; absolute discouraged
  • nyash.toml [include.roots] で std=/stdlib 等のルート定義を許可
  • 省略拡張は .nyash、ディレクトリなら index.nyash

Backends

• Interpreter: 実行時に評価し Box を返す
• VM/AOT: MIR Builder が対象ファイルを読み取り、同一 MIR モジュールに static box を降ろす（専用 MIR 命令は追加しない）

Limitations

• 循環 include の検出/診断は未実装（後続で active-load 追跡と経路表示を追加）

Rationale

• MIR 仕様に変更を入れず、実用的なモジュール分割を提供
• Everything‑is‑Box に整合（モジュール=Box、メソッド/フィールド=API）