Pack calendar definitions into per-year integers

[sugi]

概要

旧暦カレンダーテーブルの内部表現を「1年 = 整数1個 (40bit bit-pack)」に全面刷新し、メモリ消費とロード時間を大幅に削減します。あわせて required_ruby_version を 2.3 に引き上げます。

ビットレイアウト (Wareki::Calendar::PACKED[西暦年 - YEAR_MIN])

bits	内容
0..21	その年の最初の月の初日のユリウス通日
22..34	月の大小マスク (bit i = i 番目の月が大の月 = 30日)
35	閏月を含む 13 ヶ月の年フラグ
36..39	閏月の月番号 (0 = なし)

明治5年12月 (グレゴリオ切替で2日打ち切り) のみ LAST_MONTH_DAYS 定数で特別扱い。

効果 (Ruby 2.7.8 実測)

指標	旧	新
データ構造メモリ	~554KB / 8,570 オブジェクト (Struct×1428 + 配列×2856 + Hash)	~11.4KB / 配列1個 (1428×8B バッファ)
calendar_def ロード	~9.6ms	~0.3ms (~30x)
ソースサイズ	295KB	22.5KB

演算スループットは同等〜微増 (ホットパスは全 JD 域 521,542 日の roundtrip spec で担保)。

削除した API (互換なし・意図的)

Wareki::YEAR_DEFS / Wareki::YEAR_BY_NUM / Wareki::Year / Wareki::Utils.find_year。いずれも README 非記載の事実上内部 API のため 2.1.0 のマイナーバンプとし、ChangeLog に削除を明記しています。

検証

• 旧実装との全域一致: 全 521,542 日の jd→和暦、全 (年, 月, 閏) の to_jd / last_day_of_month が完全一致
• 生成データ検証: 更新した build-util/gen-jp-cal-def.rb (invariant チェック 8 種付き) の出力が移行用ブートストラップ値と Marshal 完全一致、再実行でバイト一致再現
• スイート 101 examples green (2.7.8)、Ruby 2.3.8 で全ファイル構文 OK + parse/format スモーク通過
• spec/calendar_spec.rb 追加: 境界 (JD_MIN/JD_MAX/年境界/閏月/明治5年12月) + 全域 roundtrip
• マルチエージェントレビュー実施 (タスク毎レビュー + ブランチ全体レビュー)。指摘の dangling 参照 (parse_wikipedia.rb) は修正済み

備考

• master の PR Generate era definitions from manakai data-locale #30 をマージ済み。Generate era definitions from manakai data-locale #30 由来の build-util/gen-era-def.rb も新 API に追随 (meiji_start の等価性 JD 2403357 を検証、再生成出力がコミット済み era_def.rb とバイト一致)
• kyuureki-map.txt を .gitignore に追加 (再生成手順のフットガン防止)
• CI マトリクスは 2.7.8 起点のまま (setup-ruby の古い Ruby 供給が不安定なため)。2.3 対応は手元スモークで担保

🤖 Generated with Claude Code

https://claude.ai/code/session_019zprNf9ALwJ5UgyB4hf3cK

[coveralls]

coverage: 97.336% (+0.2%) from 97.13% — feat/packed-calendar-def into master

[gemini-code-assist]

Code Review

This pull request replaces the large in-memory kyuureki calendar table with a highly efficient bit-packed integer representation in a new internal module Wareki::Calendar, reducing memory usage and significantly speeding up load times. It also raises the required Ruby version to 2.3.0 to utilize Array#bsearch_index and cleans up deprecated internal constants and methods. The review feedback recommends enhancing the robustness of the new Wareki::Calendar module by replacing non-intuitive and operators with standard if modifiers, adding input validation to month_index to handle invalid months or mismatched leap flags, and adding corresponding nil guards in last_day_of_month and to_jd.

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[Copilot]

Pull request overview

This PR refactors Wareki’s internal kyuureki (lunisolar) calendar table representation from object-heavy year definitions to a compact per-year 40-bit packed integer array, reducing memory usage and improving load time, while also raising the minimum supported Ruby version and bumping the gem version.

Changes:

• Introduce Wareki::Calendar with bit-packed calendar lookup APIs and add comprehensive boundary/roundtrip specs.
• Migrate existing consumers (Wareki::Date, Wareki::Utils, era generator) off the removed internal year-definition APIs.
• Raise required_ruby_version to >= 2.3.0 and bump version/ChangeLog for release 2.1.0.

Reviewed changes

Copilot reviewed 14 out of 16 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
wareki.gemspec	Raises minimum supported Ruby version to 2.3.0.
.rubocop.yml	Updates Ruby-version-related RuboCop comments/config.
.rubocop_todo.yml	Excludes the new spec/calendar_spec.rb from a path-format cop.
.gitignore	Ignores kyuureki-map.txt to prevent accidental commits.
lib/wareki/common.rb	Switches calendar loading from calendar_def to calendar and removes YEAR_BY_NUM.
lib/wareki/calendar.rb	Adds the packed-calendar lookup API surface (covers_*, to_jd, find_date_ary, etc.).
lib/wareki/calendar_def.rb	Replaces old year structs with generated packed integer table + constants.
lib/wareki/utils.rb	Routes lunisolar lookups through Wareki::Calendar and removes find_year.
lib/wareki/date.rb	Replaces direct year-table access with Wareki::Calendar APIs for indexing/validation/JD conversion.
build-util/gen-jp-cal-def.rb	Rewrites generator to emit packed integer calendar definitions with invariants.
build-util/gen-era-def.rb	Updates Meiji start computation to use Wareki::Calendar.to_jd and ensures repo lib is loaded.
spec/utils_spec.rb	Updates specs to use find_date_ary and checks packed definitions are frozen.
spec/calendar_spec.rb	Adds coverage for packed calendar constants, boundaries, leap months, and full-table roundtrip.
lib/wareki/version.rb	Bumps gem version from 2.0.0 to 2.1.0.
ChangeLog	Adds 2.1.0 release notes for the packed-calendar migration and Ruby requirement bump.
docs/superpowers/plans/2026-07-13-packed-calendar-def.md	Adds an implementation plan/reference document for the migration.

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[sugi]

[ClaudeCode] The -0.4% drop was Wareki::Date#month_index losing its indirect coverage: its former internal callers (_validate_date! and #jd) now go through Wareki::Calendar directly. Added a spec exercising it (lunisolar/leap/Gregorian/western paths and the out-of-range error) in 0285349 — only pre-existing uncovered lines remain.