chore: Halkyon Learn moves into apps/learn

Its server, client, app and curator, and the tools that write its
assets (maps, Anki fixtures, icons), as they are; paths are fixed in
the commits that follow.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Signed-off-by: Tizian 「ティツィアーン」 <raisondetredev@pm.me>

apps/learn/halkyon_learn_curator/test/unihan_test.dart

@@ -0,0 +1,173 @@
+import 'dart:convert';
+import 'dart:io';
+
+import 'package:archive/archive.dart';
+import 'package:halkyon_learn_curator/src/sources/cedict.dart';
+import 'package:halkyon_learn_curator/src/sources/unihan.dart';
+import 'package:halkyon_learn_curator/src/wordfreq.dart';
+import 'package:test/test.dart';
+
+void main() {
+  final unihan = Unihan.parse(
+    File('test/fixtures/unihan-sample.txt').readAsLinesSync(),
+  );
+  final cedict = File('test/fixtures/cedict-characters-sample.txt')
+      .readAsStringSync();
+  // The words' places as wordfreq's list has them (的 0, 了 3, 后 41, …).
+  final frequencies = WordFrequencies(const {
+    '了': 3,
+    '我们': 14,
+    '说': 24,
+    '为了': 170,
+    '以后': 160,
+    '后': 41,
+    '学习': 380,
+    '了解': 520,
+    '这': 15,
+    '水': 600,
+    '银行': 1900,
+    '皇后': 9000,
+  });
+  final places = cedictCharacterPlaces(cedict, frequencies);
+
+  /// The entries of a dictionary file's [lines], by character.
+  Map<String, Map<String, Object?>> entriesOf(Iterable<String> lines) => {
+    for (final line in lines.skip(1))
+      if (jsonDecode(line) case final Map<String, Object?> entry)
+        entry['headword']! as String: entry,
+  };
+
+  test("the simplified characters are the standard's, with pinyin, the "
+      'usual reading first, meanings, strokes, radical and HSK level', () {
+    final lines = chineseCharacters(
+      unihan,
+      traditional: false,
+      sourceVersion: '18.0.0',
+      hsk: const {'说': 1, '行': 1, '后': 1},
+      places: places,
+    ).toList();
+
+    final header = jsonDecode(lines.first) as Map<String, Object?>;
+    expect(header['source'], 'unihan-hans');
+    expect(header['kind'], 'characters');
+    expect(header['language'], 'zh-Hans');
+    expect(header['sourceVersion'], '18.0.0');
+    final entries = entriesOf(lines);
+    // No traditional character among them.
+    expect(entries.keys, isNot(contains('說')));
+    expect(entries.keys, containsAll(['说', '这', '后', '了', '行', '水']));
+    final xing = entries['行']!;
+    expect(((xing['entry']! as Map)['pinyin'] as List).take(2), [
+      'xíng',
+      'háng',
+    ]);
+    expect((xing['entry']! as Map)['strokes'], 6);
+    expect(xing['labels'], ['hsk:1', 'common', 'radical:144']);
+    final shuo = entries['说']!;
+    expect((shuo['entry']! as Map)['meanings'], [
+      'speak',
+      'say',
+      'talk',
+      'scold',
+      'upbraid',
+    ]);
+    expect((shuo['entry']! as Map)['traditional'], ['說', '説']);
+    // Found by its pinyin with marks, without, and numbered; written in
+    // the other script, loosely.
+    expect(shuo['keys'], containsAll(['shuō', 'shuo', 'shuo1', 'speak']));
+    expect(shuo['looseKeys'], ['說', '説']);
+  });
+
+  test('the traditional characters are those words in use write: 這 and 了, '
+      'not 这; 後 the usual form of 后, ranked and levelled as it', () {
+    final entries = entriesOf(
+      chineseCharacters(
+        unihan,
+        traditional: true,
+        hsk: const {'后': 1, '了': 1},
+        places: places,
+      ),
+    );
+
+    expect(entries.keys, containsAll(['這', '了', '瞭', '後', '后', '說']));
+    expect(entries.keys, isNot(contains('这')));
+    // 後 takes 后's place and level; 后, the queen, ranks by its own words.
+    expect(entries['後']!['labels'], contains('hsk:1'));
+    expect(entries['后']!['labels'], isNot(contains('hsk:1')));
+    expect(
+      entries['後']!['rank']! as int,
+      lessThan(entries['后']!['rank']! as int),
+    );
+    // 了 stands for itself; 瞭 is a form of it of its own.
+    expect(entries['了']!['labels'], contains('hsk:1'));
+    expect(entries['瞭']!['labels'], isNot(contains('hsk:1')));
+    expect((entries['說']!['entry']! as Map)['simplified'], ['说']);
+    // Hong Kong's primary schools teach 說 in the first grade.
+    expect(entries['說']!['labels'], contains('grade:1'));
+  });
+
+  test("CC-CEDICT's words tell each script's characters their places: a "
+      "lone simplified character's to the traditional form longer words use "
+      'most', () {
+    expect(places.simplified['后'], 41);
+    expect(places.traditional['後'], 41);
+    expect(places.traditional['后'], 9000);
+    expect(places.traditional['了'], 3);
+    // 瞭解 is only a variant of 了解 there, and 了 the form 為了 uses.
+    expect(places.traditional, isNot(contains('瞭')));
+    expect(places.traditional, isNot(contains('这')));
+  });
+
+  test('Korean Hanja with their sounds, the taught one first, their native '
+      'readings from Wiktionary, and the Hangul letters before them', () {
+    final lines = koreanHanja(
+      unihan,
+      sourceVersion: '18.0.0',
+      eumhun: const {
+        '水': [(hun: '물', eum: '수')],
+      },
+    ).toList();
+
+    final header = jsonDecode(lines.first) as Map<String, Object?>;
+    expect(header['language'], 'ko');
+    expect(header['license'], 'CC-BY-SA-4.0');
+    expect([
+      for (final credit in header['credits']! as List) (credit as Map)['name'],
+    ], containsAll(['Unihan Database', 'Wiktionary']));
+    final entries = entriesOf(lines);
+    final water = entries['水']!;
+    expect(water['entry'], {
+      'meanings': ['water', 'liquid', 'lotion', 'juice'],
+      'eum': ['수'],
+      'hun': ['물'],
+      'eumhun': ['물 수'],
+      'strokes': 4,
+    });
+    expect(water['labels'], ['education', 'radical:85']);
+    expect(water['keys'], containsAll(['水', '수', '물', '물 수', 'water']));
+    // 行 is taught as 행, also read 항.
+    expect((entries['行']!['entry']! as Map)['eum'], ['행', '항']);
+    final giyeok = entries['ㄱ']!;
+    expect(giyeok['labels'], ['hangul']);
+    expect(giyeok['entry'], {
+      'romaji': 'g, k',
+      'script': 'hangul',
+      'name': '기역',
+    });
+    expect(giyeok['rank']! as int, lessThan(water['rank']! as int));
+  });
+
+  test("Unihan's zip is read whole, with the version of Unicode it is of", () {
+    final archive = Archive()
+      ..add(
+        ArchiveFile.bytes(
+          'Unihan_Readings.txt',
+          File('test/fixtures/unihan-sample.txt').readAsBytesSync(),
+        ),
+      );
+    final (:unihan, :version) = Unihan.ofZip(ZipEncoder().encodeBytes(archive));
+
+    expect(version, '18.0.0');
+    expect(unihan.characters, contains('水'));
+  });
+}