/// <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>
/// Attempts to solve furigana by reading the kanji reading string and finding matching kanji
/// kanji readings.
/// </summary>
protected override IEnumerable <FuriganaSolution> DoSolve(FuriganaResourceSet r, VocabEntry v)
{
foreach (FuriganaSolution solution in TryReading(r, v, 0, 0, new List <FuriganaPart>()))
{
yield return(solution);
}
}
/// <summary>
/// Attempts to solve cases where the length of the kanji reading matches the length of the
/// kana reading.
/// </summary>
protected override IEnumerable <FuriganaSolution> DoSolve(FuriganaResourceSet r, VocabEntry v)
{
if (v.KanjiReading.Length == v.KanaReading.Length)
{
List <FuriganaPart> parts = new List <FuriganaPart>();
for (int i = 0; i < v.KanjiReading.Length; i++)
{
if (r.GetKanji(v.KanjiReading[i]) != null)
{
parts.Add(new FuriganaPart(v.KanaReading[i].ToString(), i));
}
else if (!KanaHelper.IsAllKana(v.KanjiReading[i].ToString()))
{
// Our character is not a kanji and apparently not a kana either.
// Stop right there. It's probably a trap.
yield break;
}
else
{
if (!KanaHelper.AreEquivalent(v.KanjiReading[i].ToString(), v.KanaReading[i].ToString()))
{
// We are reading kana characters that are not equivalent. Stop.
yield break;
}
}
}
if (parts.Any())
{
yield return(new FuriganaSolution(v, parts));
}
}
}
/// <summary>
/// Attempts to solve furigana when the kanji reading only has one character.
/// </summary>
protected override IEnumerable <FuriganaSolution> DoSolve(FuriganaResourceSet r, VocabEntry v)
{
if (v.KanjiReading.Length == 1 && !KanaHelper.IsAllKana(v.KanjiReading))
{
yield return(new FuriganaSolution(v, new FuriganaPart(v.KanaReading, 0, 0)));
}
}
/// <summary>
/// Recursive method that reads the kanji reading string and attempts to find all the ways the
/// kana reading could be cut by matching it with the potential kanji readings.
/// </summary>
/// <param name="r">Resource set.</param>
/// <param name="v">Vocab to solve.</param>
/// <param name="currentIndexKanji">Current position in the kanji string. Used for recursion.</param>
/// <param name="currentIndexKana">Current position in the kana string. Used for recursion.</param>
/// <param name="currentCut">Current furigana parts. Used for recursion.</param>
private IEnumerable <FuriganaSolution> TryReading(FuriganaResourceSet r, VocabEntry v,
int currentIndexKanji, int currentIndexKana, List <FuriganaPart> currentCut)
{
if (currentIndexKanji == v.KanjiReading.Length && currentIndexKana == v.KanaReading.Length)
{
// We successfuly read the word and stopped at the last character in both kanji and kana readings.
// Our current cut is valid. Return it.
yield return(new FuriganaSolution(v, currentCut));
yield break;
}
else if (currentIndexKanji >= v.KanjiReading.Length || currentIndexKana >= v.KanaReading.Length)
{
// Broken case. Do not return anything.
yield break;
}
// Search for special expressions.
bool foundSpecialExpressions = false;
foreach (FuriganaSolution solution in FindSpecialExpressions(r, v, currentIndexKanji, currentIndexKana, currentCut))
{
foundSpecialExpressions = true;
yield return(solution);
}
if (foundSpecialExpressions)
{
yield break;
}
// General case. Get the current character and see if it is a kanji.
char c = v.KanjiReading[currentIndexKanji];
if (c == '々' && currentIndexKanji > 0)
{
// Special case: handle the repeater kanji by using the previous character instead.
c = v.KanjiReading[currentIndexKanji - 1];
}
Kanji k = r.GetKanji(c);
if (k != null)
{
// Read as kanji subpart.
foreach (FuriganaSolution solution in ReadAsKanji(r, v, currentIndexKanji, currentIndexKana, currentCut, c, k))
{
yield return(solution);
}
}
else
{
// Read as kana subpart.
foreach (FuriganaSolution solution in ReadAsKana(r, v, currentIndexKanji, currentIndexKana, currentCut, c))
{
yield return(solution);
}
}
}
/// <summary>
/// Attempts to solve the given vocab entry.
/// </summary>
/// <param name="r">Set of resources required by solvers.</param>
/// <param name="v">Entry to attempt to solve.</param>
/// <returns>The solutions found, if any.</returns>
public IEnumerable <FuriganaSolution> Solve(FuriganaResourceSet r, VocabEntry v)
{
foreach (FuriganaSolution solution in DoSolve(r, v))
{
if (!solution.Check())
{
throw new Exception("The solution did not pass the check test.");
}
yield return(solution);
}
}
/// <summary>
/// Solves cases where the kanji reading consists in a repeated kanji.
/// </summary>
protected override IEnumerable <FuriganaSolution> DoSolve(FuriganaResourceSet r, VocabEntry v)
{
if (v.KanjiReading.Length == 2 && v.KanaReading.Length % 2 == 0 &&
(v.KanjiReading[1] == '々' || v.KanjiReading[1] == v.KanjiReading[0]))
{
// We have a case where the kanji string is composed of kanji repeated (e.g. 中々),
// and our kana string can be cut in two. Just do that.
yield return(new FuriganaSolution(v,
new FuriganaPart(v.KanaReading.Substring(0, v.KanaReading.Length / 2), 0),
new FuriganaPart(v.KanaReading.Substring(v.KanaReading.Length / 2), 1)));
}
}
/// <summary>
/// Attempts to solve furigana by looking up for solutions in the override list.
/// </summary>
protected override IEnumerable <FuriganaSolution> DoSolve(FuriganaResourceSet r, VocabEntry v)
{
FuriganaSolution solution = r.GetOverride(v);
if (solution != null)
{
yield return(new FuriganaSolution()
{
Furigana = solution.Furigana,
Vocab = v
});
}
}
/// <summary>
/// Subpart of TryReading. Attempts to find a match between the current kanji reading character
/// and the current kana reading character. If found, iterates on TryReading.
/// </summary>
private IEnumerable <FuriganaSolution> ReadAsKana(FuriganaResourceSet r, VocabEntry v,
int currentIndexKanji, int currentIndexKana, List <FuriganaPart> currentCut, char c)
{
char kc = v.KanaReading[currentIndexKana];
if (c == kc || KanaHelper.ToHiragana(c.ToString()) == KanaHelper.ToHiragana(kc.ToString()))
{
// What we are reading in the kanji reading matches the kana reading.
// We can iterate with the same cut (no added furigana) because we are reading kana.
foreach (FuriganaSolution result in TryReading(r, v, currentIndexKanji + 1, currentIndexKana + 1, currentCut))
{
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 in cases where there are no consecutive kanji in the kanji string,
/// using regular expressions.
/// </summary>
protected override IEnumerable <FuriganaSolution> DoSolve(FuriganaResourceSet r, VocabEntry v)
{
// We are using both a greedy expression and a lazy expression because we want to make sure
// there is only one way to read them. If the result differs with a greedy or a lazy expression,
// it means that we have no idea how to read the damn thing.
string regGreedy = "^";
string regLazy = "^";
bool consecutiveMarker = false;
List <int> kanjiIndexes = new List <int>(4);
for (int i = 0; i < v.KanjiReading.Length; i++)
{
char c = v.KanjiReading[i];
Kanji k = r.GetKanji(c);
if (k == null)
{
// Add the characters to the string. No capture group for kana.
regGreedy += string.Format(c.ToString());
regLazy += string.Format(c.ToString());
consecutiveMarker = false;
}
else if (consecutiveMarker)
{
// Consecutive kanji. The vocab entry is not eligible for this solution.
yield break;
}
else
{
// Add the characters inside a capture group for kanji.
regGreedy += "(.+)";
regLazy += "(.+?)";
consecutiveMarker = true;
kanjiIndexes.Add(i);
}
}
regGreedy += "$";
regLazy += "$";
// Example regex:
// For 持ち運ぶ (もちはこぶ)
// The regexes would be:
// ^(.+)ち(.+)ぶ$
// ^(.+?)ち(.+?)ぶ$
Regex regexGreedy = new Regex(regGreedy);
Regex regexLazy = new Regex(regLazy);
Match matchGreedy = regexGreedy.Match(v.KanaReading);
Match matchLazy = regexLazy.Match(v.KanaReading);
if (matchGreedy.Success && matchLazy.Success)
{
// Obtain both solutions.
FuriganaSolution greedySolution = MakeSolutionFromMatch(v, matchGreedy, kanjiIndexes);
FuriganaSolution lazySolution = MakeSolutionFromMatch(v, matchLazy, kanjiIndexes);
// Are both solutions non-null and equivalent?
if (greedySolution != null && lazySolution != null && greedySolution.Equals(lazySolution))
{
// Yes they are! Return only one of them of course.
// Greedy wins obviously.
yield return(greedySolution);
}
}
}
/// <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));
}
}
protected abstract IEnumerable <FuriganaSolution> DoSolve(FuriganaResourceSet r, VocabEntry v);
protected override IEnumerable <FuriganaSolution> DoSolve(FuriganaResourceSet r, VocabEntry v)
{
int kanjiCount = v.KanjiReading.Count(c => r.GetKanji(c) != null);
if (kanjiCount == 1)
{
int kanjiIndex = 0;
string kanaReading = v.KanaReading;
// See if there are only obvious characters around.
// Browse the kanji reading and eat characters until we get to
// the kanji character.
for (int i = 0; i < v.KanjiReading.Length; i++)
{
char c = v.KanjiReading[i];
Kanji k = r.GetKanji(c);
if (k == null)
{
if (kanaReading.First() == c)
{
// Remove the first character of the reading.
kanaReading = kanaReading.Substring(1);
}
else
{
// There is something wrong. Readings don't add up.
// Can't solve.
yield break;
}
}
else
{
// We are on the kanji. Skip.
kanjiIndex = i;
break;
}
}
// Now browse in reverse and eat characters until we get back to
// the kanji character.
for (int i = v.KanjiReading.Length - 1; i >= 0; i--)
{
char c = v.KanjiReading[i];
Kanji k = r.GetKanji(c);
if (k == null)
{
if (kanaReading.Last() == c)
{
// Eat the last character of the reading.
kanaReading = kanaReading.Substring(0, kanaReading.Length - 1);
}
else
{
// There is something wrong. Readings don't add up.
// Can't solve.
yield break;
}
}
else
{
// We are on the kanji. Skip.
break;
}
}
// We are done. Our kanaReading contains only what's left when eating the kana
// before and after the kanji. It's the reading of our kanji.
yield return(new FuriganaSolution(v, new FuriganaPart(kanaReading, kanjiIndex)));
}
}
