/// <summary>
/// 处理最后一个字符
/// </summary>
/// <param name="text"></param>
/// <param name="currentIndex"></param>
/// <param name="result"></param>
private void ProcessLastChar(string text, int currentIndex, AuxiliaryString auxString, string lastMaxLenElement)
{
//如果最后一个字符还没有处理
if (currentIndex < text.Length && !lastMaxLenElement.EndsWith(text.Substring(text.Length - 1)))
{
auxString.Append(text.Substring(text.Length - 1),currentIndex);
auxString.Append(this.Separator);
}
}
/// <summary>
/// 处理非汉字
/// </summary>
/// <param name="text"></param>
/// <param name="result"></param>
/// <param name="currentChar"></param>
/// <param name="currentIndex"></param>
private void ProcessNonChinese(string text, AuxiliaryString auxString, string currentChar, string nextChar, int currentIndex)
{
if (currentChar == " ")
{
//当前是空格
}
else
{
if (nextChar == " ")
{
auxString.Append(currentChar, currentIndex);
auxString.Append(this.Separator);
}
else
{
if ((Character.IsLetter(currentChar) && !Character.IsLetter(nextChar)) ||
Character.IsNumber(currentChar) && Character.IsLetter(nextChar))
{
//当前字符是字母，且下一字符不是字母。
//或者当前是数字，且下一字符是字母
auxString.Append(currentChar, currentIndex);
auxString.Append(this.Separator);
}
else
{
//当前字符是数字
auxString.Append(currentChar, currentIndex);
}
}
}
}
/// <summary>
/// 以当前两字符开头的词，在词库中存在,取出所有匹配的词并抽取最大程度的词。
/// </summary>
/// <param name="text"></param>
/// <param name="result"></param>
/// <param name="currentTwoChars"></param>
/// <param name="currentIndex"></param>
/// <returns></returns>
private void ProcessExistingElement(string text, AuxiliaryString auxString,
string currentChar, string currentTwoChars, ref int currentIndex, ref string maxLenElement)
{
int maxlen = this.SegmentDictionary.SegmentKeys[currentChar][currentTwoChars] > (text.Length - currentIndex) ? (text.Length - currentIndex) : this.SegmentDictionary.SegmentKeys[currentChar][currentTwoChars];
bool exist = false;
//找到以当前字符开头存在于词典中的最长词
for (int i = maxlen; i >= 2; i--)
{
string element = text.Substring(currentIndex, i);
if (this.SegmentDictionary.SegmentDict.ContainsKey(element))
{
maxLenElement = element;
exist = true;
break;
}
}
if (!exist)//没有找到，不存在以当前字符为首的词
{
auxString.Append(currentChar, currentIndex);
auxString.Append(this.Separator);
return;
}
if (!auxString.NeedAddPos && currentIndex > 0)
{
auxString.Append(currentTwoChars, currentIndex);
auxString.Append(this.Separator);
} //找到，分解这个最长词
string strLeave = maxLenElement;
bool remove = false;
int minLen = 2;
int startpos = currentIndex;
while (strLeave.Length >= 2)
{
remove = false;
for (int j = 2; j <= strLeave.Length; j++)
{
string subElement = strLeave.Substring(0, j);
if (this.SegmentDictionary.SegmentDict.ContainsKey(subElement))
{
auxString.Append(subElement,startpos);
auxString.Append(this.Separator);
if (!remove)
{
remove = true;
minLen = subElement.Length;
}
}
}
strLeave = strLeave.Substring(minLen);
startpos += minLen;
}
currentIndex += maxLenElement.Length - 1;
}
/// <summary>
/// 对单个句子分词。
/// </summary>
/// <param name="text"></param>
/// <param name="result"></param>
protected override void SegmentSentence(string text, ref StringBuilder result, out List<int> startList)
{
startList = new List<int>();
if (string.IsNullOrEmpty(text))
{
return;
}
if (this.SegmentDictionary.Segments.Count <= 0)
{
return;
}
string currentChar;
string nextChar;
string currentTwoChars;
string maxLenElement = "";
int charCursor = 0;
AuxiliaryString auxString = new AuxiliaryString();
for (charCursor = 0; charCursor < text.Length - 1; charCursor++)
{
currentChar = text.Substring(charCursor, 1);
nextChar = text.Substring(charCursor + 1, 1);
//非汉字
if (!Character.IsChinese(currentChar))
{
ProcessNonChinese(text, auxString, currentChar, nextChar, charCursor);
continue;
}
//下一字符非汉字
if (!Character.IsChinese(nextChar))
{
auxString.Append(currentChar,charCursor);
auxString.Append(this.Separator);
continue;
}
//汉字
currentTwoChars = text.Substring(charCursor, 2);
//以当前两字符开头的词，在词库中不存在
if (!this.SegmentDictionary.Segments.ContainsKey(currentTwoChars))
{
//当前字符是姓
if (this.NameSegments.ContainsKey(currentChar))
{
auxString.Append(currentChar,charCursor);
}
else if (this.NameSegments.ContainsKey(currentTwoChars))
{
auxString.Append(currentTwoChars,charCursor);
}
else
{
auxString.Append(currentChar,charCursor);
auxString.Append(this.Separator);
}
continue;
}
//以当前两字符开头的词，在词库中存在,取出所有匹配的词并抽取最大程度的词。
ProcessExistingElement(text, auxString, currentChar, currentTwoChars, ref charCursor, ref maxLenElement);
}
//处理最后一个字符
ProcessLastChar(text, charCursor, auxString, maxLenElement);
result = auxString.Builder;
startList = auxString.StartList;
}