/// <summary>
/// Subpart of TryReading. Attempts to find a matching special expression.
/// If found, iterates on TryReading.
/// </summary>
private IEnumerable <FuriganaSolution> FindSpecialExpressions(FuriganaResourceSet r, VocabEntry v,
int currentIndexKanji, int currentIndexKana, List <FuriganaPart> currentCut)
{
string lookup = string.Empty;
for (int i = v.KanjiReading.Length - 1; i >= currentIndexKanji; i--)
{
lookup = v.KanjiReading.Substring(currentIndexKanji, (i - currentIndexKanji) + 1);
SpecialExpression expression = r.GetExpression(lookup);
if (expression != null)
{
foreach (SpecialReading expressionReading in ReadingExpander.GetPotentialSpecialReadings(
expression, currentIndexKanji == 0, i == v.KanjiReading.Length - 1))
{
if (v.KanaReading.Length >= currentIndexKana + expressionReading.KanaReading.Length &&
v.KanaReading.Substring(currentIndexKana, expressionReading.KanaReading.Length) == expressionReading.KanaReading)
{
// The reading matches. Iterate with this possibility.
List <FuriganaPart> newCut = currentCut.Clone();
newCut.AddRange(expressionReading.Furigana.Furigana
.Select(fp => new FuriganaPart(fp.Value, fp.StartIndex + currentIndexKanji, fp.EndIndex + currentIndexKanji)));
foreach (FuriganaSolution result in TryReading(r, v, i + 1,
currentIndexKana + expressionReading.KanaReading.Length, newCut))
{
yield return(result);
}
}
}
}
}
}
/// <summary>
/// Subpart of TryReading. Finds all matching kanji readings for the current situation,
/// and iterates on TryReading when found.
/// </summary>
private IEnumerable <FuriganaSolution> ReadAsKanji(FuriganaResourceSet r, VocabEntry v,
int currentIndexKanji, int currentIndexKana, List <FuriganaPart> currentCut, char c, Kanji k)
{
// Our character is a kanji. Try to consume kana strings that match that kanji.
int remainingKanjiLength = v.KanjiReading.Length - currentIndexKanji - 1;
List <string> kanjiReadings = ReadingExpander.GetPotentialKanjiReadings(k,
currentIndexKanji == 0, currentIndexKanji == v.KanjiReading.Length - 1, UseNanori);
// Iterate on the kana reading.
for (int i = currentIndexKana; i < v.KanaReading.Length && i < currentIndexKana + MaxKanaPerKanji; i++)
{
int remainingKanaLength = v.KanaReading.Length - i - 1;
if (remainingKanaLength < remainingKanjiLength)
{
// We consumed too many characters: not enough kana remaining for the number of kanji.
// Stop here. There are no more solutions.
yield break;
}
// Get the kana string between currentIndexKana and i.
string testedString = v.KanaReading.Substring(currentIndexKana, (i - currentIndexKana) + 1);
// Now try to match that string against one of the potential readings of our kanji.
foreach (string reading in kanjiReadings)
{
if (reading == testedString)
{
// We have a match.
// Create our new cut and iterate with it.
List <FuriganaPart> newCut = currentCut.Clone();
newCut.Add(new FuriganaPart(reading, currentIndexKanji));
foreach (FuriganaSolution result in TryReading(r, v, currentIndexKanji + 1, i + 1, newCut))
{
yield return(result);
}
}
}
// Continue to expand our testedString to try and follow other potential reading paths.
}
}
/// <summary>
/// Attempts to solve furigana by reading the kana string and attributing kanji a reading based
/// not on the readings of the kanji, but on the kana characters that come up.
/// </summary>
protected override IEnumerable <FuriganaSolution> DoSolve(FuriganaResourceSet r, VocabEntry v)
{
// Basically, we are reading the kanji reading character by character, eating the kana from
// the kana reading and associating each kanji the piece of kana that comes next.
// The thing is, we are taking advantage that kanji readings cannot start with certain
// kana (ん and the small characters).
// If we just stumbled upon a kanji and the next characters of the kana string are of these
// impossible start kana, we can automatically associate them with the kanji.
// Now this will work only for a number of vocab, but it does significantly improve the results.
// It is especially good for 2-characters compounds that use unusual readings.
/// Example: 阿呆陀羅 (あほんだら)
/// Read the あ for 阿;
/// Read the ほ for 呆;
/// Read the ん: it's an impossible start character, so it goes with 呆 as well;
/// Read the だ for 陀;
/// Read the ら for 羅.
string kana = v.KanaReading;
List <FuriganaPart> furigana = new List <FuriganaPart>();
for (int i = 0; i < v.KanjiReading.Length; i++)
{
if (kana.Length == 0)
{
// We still have characters to browse in our kanji reading, but
// there are no more kana to consume. Cannot solve.
yield break;
}
char c = v.KanjiReading[i];
// Check for special expressions
bool foundExpression = false;
for (int j = v.KanjiReading.Length - 1; j >= i; j--)
{
string lookup = v.KanjiReading.Substring(i, (j - i) + 1);
SpecialExpression expression = r.GetExpression(lookup);
if (expression != null)
{
// We found an expression.
foreach (SpecialReading expressionReading in ReadingExpander.GetPotentialSpecialReadings(
expression, i == 0, j == v.KanjiReading.Length - 1))
{
if (kana.Length >= expressionReading.KanaReading.Length &&
kana.Substring(0, expressionReading.KanaReading.Length) == expressionReading.KanaReading)
{
// The reading matches.
// Eat the kana chain.
furigana.AddRange(expressionReading.Furigana.Furigana
.Select(fp => new FuriganaPart(fp.Value, fp.StartIndex + i, fp.EndIndex + i)));
kana = kana.Substring(expressionReading.KanaReading.Length);
i = j;
foundExpression = true;
break;
}
}
if (foundExpression)
{
break;
}
}
}
if (foundExpression)
{
continue;
}
// Normal process: eat the first character of our kana string.
string eaten = kana.First().ToString();
kana = kana.Substring(1);
Kanji k = r.GetKanji(c);
if (k != null)
{
// On a kanji case, also eat consecutive "impossible start characters"
// (ん, ょ, ゃ, ゅ, っ)
while (kana.Length > 0 && ImpossibleCutStart.Contains(kana.First()))
{
eaten += kana.First();
kana = kana.Substring(1);
}
furigana.Add(new FuriganaPart(eaten, i));
}
else if (!KanaHelper.IsAllKana(c.ToString()))
{
// The character is neither a kanji or a kana.
// Cannot solve.
yield break;
}
else
{
if (eaten != c.ToString())
{
// The character browsed is a kana but is not the
// character that we just ate. We made a mistake
// in one of the kanji readings, meaning that we...
// Cannot solve.
yield break;
}
}
}
if (kana.Length == 0)
{
// We consumed the whole kana string.
// The case is solved.
yield return(new FuriganaSolution(v, furigana));
}
}