public static string ConvertRomajiToHiragana(string romaji)
{
if (romaji.Length == 0)
{
return("");
}
var hiragana = new StringBuilder();
var start = 0;
var end = 1;
while (start < romaji.Length)
{
var lastFound = -1;
var lower = 0;
var upper = ROMAN_INDEXES.Length;
while (upper - lower > 1 && end <= romaji.Length)
{
var lowerKey = RomanEntry.CalculateIndex(romaji, start, end);
lower = Array.BinarySearch(ROMAN_INDEXES, lower, upper - lower, lowerKey);
if (lower >= 0)
{
lastFound = lower;
}
else
{
lower = -lower - 1;
}
uint upperKey = lowerKey + (uint)(1 << (32 - 8 * (end - start)));
upper = Array.BinarySearch(ROMAN_INDEXES, lower, upper - lower, upperKey);
if (upper < 0)
{
upper = -upper - 1;
}
end++;
}
if (lastFound >= 0)
{
var entry = ROMAN_ENTRIES[lastFound];
hiragana.Append(entry.Hiragana);
start = start + entry.Roman.Length - entry.Remain;
end = start + 1;
}
else
{
hiragana.Append(romaji[start]);
start++;
end = start + 1;
}
}
return(hiragana.ToString());
}
public static ISet <RomanEntry> FindRomanEntryPredicatively(string roman, int offset)
{
var lastFound = -1;
var startIndex = 0;
var endIndex = ROMAN_INDEXES.Length;
for (var i = 0; i < 4; i++)
{
if (roman.Length <= offset + i)
{
break;
}
var startKey = RomanEntry.CalculateIndex(roman, offset, offset + i + 1);
startIndex = Array.BinarySearch(ROMAN_INDEXES, startIndex, endIndex - startIndex, startKey);
if (startIndex >= 0)
{
lastFound = startIndex;
}
else
{
startIndex = -startIndex - 1;
}
var endKey = startKey + (uint)(1 << (24 - 8 * i));
endIndex = Array.BinarySearch(ROMAN_INDEXES, startIndex, endIndex - startIndex, endKey);
if (endIndex < 0)
{
endIndex = -endIndex - 1;
}
if (endIndex - startIndex == 1)
{
return(new HashSet <RomanEntry>()
{
ROMAN_ENTRIES[startIndex]
});
}
}
var result = new HashSet <RomanEntry>();
for (var i = startIndex; i < endIndex; i++)
{
result.Add(ROMAN_ENTRIES[i]);
}
return(result);
}
public static RomajiPredictiveResult RomajiToHiraganaPredictively(string romaji)
{
if (romaji.Length == 0)
{
return(new RomajiPredictiveResult("", new HashSet <string>()
{
""
}));
}
var hiragana = new StringBuilder();
var start = 0;
var end = 1;
while (start < romaji.Length)
{
var lastFound = -1;
var lower = 0;
var upper = ROMAN_INDEXES.Length;
while (upper - lower > 1 && end <= romaji.Length)
{
var lowerKey = RomanEntry.CalculateIndex(romaji, start, end);
lower = Array.BinarySearch(ROMAN_INDEXES, lower, upper - lower, lowerKey);
if (lower >= 0)
{
lastFound = lower;
}
else
{
lower = -lower - 1;
}
var upperKey = lowerKey + (uint)(1 << (32 - 8 * (end - start)));
upper = Array.BinarySearch(ROMAN_INDEXES, lower, upper - lower, upperKey);
if (upper < 0)
{
upper = -upper - 1;
}
end++;
}
if (end > romaji.Length && upper - lower > 1)
{
var set = new HashSet <string>();
for (var i = lower; i < upper; i++)
{
var re = ROMAN_ENTRIES[i];
if (re.Remain > 0)
{
var set2 = FindRomanEntryPredicatively(romaji, end - 1 - re.Remain);
foreach (var re2 in set2)
{
if (re2.Remain == 0)
{
set.Add(re.Hiragana + re2.Hiragana);
}
}
}
else
{
set.Add(re.Hiragana);
}
}
return(new RomajiPredictiveResult(hiragana.ToString(), set));
}
if (lastFound >= 0)
{
var entry = ROMAN_ENTRIES[lastFound];
hiragana.Append(entry.Hiragana);
start = start + entry.Roman.Length - entry.Remain;
end = start + 1;
}
else
{
hiragana.Append(romaji[start]);
start++;
end = start + 1;
}
}
return(new RomajiPredictiveResult(hiragana.ToString(), new HashSet <string>()
{
""
}));
}
