Menci
53 lines
2.2 KiB
C#
53 lines
2.2 KiB
C#
using MaigoLabs.NeedLe.Indexer.Han;
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using MyNihongo.KanaConverter;
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namespace MaigoLabs.NeedLe.Indexer.Japanese;
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public static class JapaneseUtils
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{
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public static bool IsMaybeJapanese(int codePoint) =>
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HanVariantProvider.IsHanCharacter(codePoint) ||
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IsKana(codePoint) ||
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IsJapaneseSoundMark(codePoint) ||
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codePoint == 0x3005 || codePoint == 0x3006 || codePoint == 0x30FC;
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// See also Common/Normalization.cs
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public static bool IsJapaneseSoundMark(int codePoint) => codePoint == 0x3099 || codePoint == 0x309A;
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public static string StripJapaneseSoundMarks(string text) => string.Concat(text.Where(codePoint => !IsJapaneseSoundMark(codePoint)));
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public static bool IsKana(int codePoint) => (codePoint >= 0x3041 && codePoint <= 0x309F) || (codePoint >= 0x30A0 && codePoint <= 0x30FF);
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private static readonly int[] KANAS_CANNOT_BE_FIRST =
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[
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'ァ', 'ィ', 'ゥ', 'ェ', 'ォ',
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'ぁ', 'ぃ', 'ぅ', 'ぇ', 'ぉ',
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'ャ', 'ュ', 'ョ',
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'ゃ', 'ゅ', 'ょ',
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'ヮ', 'ゎ',
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'ㇰ', 'ㇱ', 'ㇲ', 'ㇳ', 'ㇴ', 'ㇵ', 'ㇶ', 'ㇷ', 'ㇸ', 'ㇹ', 'ㇺ', 'ㇻ', 'ㇼ', 'ㇽ', 'ㇾ', 'ㇿ',
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'ー',
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];
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private static readonly int[] KANAS_CANNOT_BE_LAST =
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[
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'ッ', 'っ'
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];
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public static string ToRomajiStrictly(string kanaText)
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{
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if (kanaText.Length == 0) return "";
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if (KANAS_CANNOT_BE_FIRST.Contains(kanaText[0])) return "";
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if (KANAS_CANNOT_BE_LAST.Contains(kanaText[^1])) return "";
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string romaji;
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try { romaji = kanaText.ToRomaji(); }
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catch { return ""; }
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if (!romaji.All(c => c is >= 'a' and <= 'z')) return "";
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return romaji;
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}
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public static bool IsValidJapanesePhrase(ReadOnlySpan<int> codePoints, int start, int length) =>
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// Skip splittings that cause sound marks to occur in the first position of a phrase
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!IsJapaneseSoundMark(codePoints[start]) && (start + length == codePoints.Length || !IsJapaneseSoundMark(codePoints[start + length]));
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public static bool IsValidJapanesePhrase(ReadOnlyMemory<int> codePoints, int start, int length) => IsValidJapanesePhrase(codePoints.Span, start, length);
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}
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