/// <summary>
/// Rule #1 (Ukkonen's first group of t_i-transitions): Try to find matching edge for the parent node.
/// </summary>
/// <param name="parentNode">This is a member of active. It is kept separate for clarity.</param>
private ExtensionResult extendSuffixByRuleOne(
ref GstSuffix active, ref GstNode parentNode, int endIndex, int wordNum)
{
if (active.IsExplicit)
{
GstEdge edge = active.OriginNode.GetChildEdge(GetWordChar(wordNum, endIndex));
if (edge != null && edge.IsSet())
{
return(ExtensionResult.Done);
}
}
else // active suffix is implicit
{
GstEdge edge = active.OriginNode.GetChildEdge(GetWordChar(wordNum, active.BeginIndex));
int span = active.EndIndex - active.BeginIndex;
if (edge != null)
{
int extantWordNum = edge.GetExtantWordNum();
if (GetWordChar(extantWordNum, edge.GetBeginIndex(extantWordNum) + span + 1)
== GetWordChar(wordNum, endIndex))
{
return(ExtensionResult.Done);
}
GstUtil.WriteLine(GstVerbosityLevel.Verbose, String.Format(
" Rule #1: About to split edge E{0:d} (\"{1:s}\") at suffix {2:s}",
edge.Id, edge.GetText(), active.ToString()));
parentNode = edge.Split(active);
}
}
return(ExtensionResult.NotDone);
}
private bool AddWord(string word, bool doConsoleVerbose = false)
{
if (word == null || word.Length == 0)
{
return(false);
}
GstUtil.WriteLine(GstVerbosityLevel.Verbose, new String('-', 40));
int wordNum = wordCount++;
wordDict[wordNum] = word;
GstUtil.WriteLine(GstVerbosityLevel.Verbose, String.Format(
"Adding word #{0:d} (\"{1:s}\") to the suffix tree",
wordNum, wordDict[wordNum]));
GstSuffix active = new GstSuffix(this, root, wordNum, 0, GSuffixTree.InfiniteIndex);
GstUtil.WriteLine(GstVerbosityLevel.Verbose, String.Format(
"Created active (longest proper) suffix pointer: {0:s}",
active.ToString()));
int endIndex = 0;
if (wordNum > 0)
{
skipDuplicateInitialSubstring(ref active, ref endIndex, wordNum);
if (endIndex > 0)
{
GstUtil.WriteLine(GstVerbosityLevel.Verbose, String.Format(
"The first {0:d} letter(s) of word #{1:d} are already in the suffix tree",
endIndex, wordNum));
}
}
for ( ; endIndex < wordDict[wordNum].Length; endIndex++)
{
GstUtil.WriteLine(GstVerbosityLevel.Verbose, this.ToString());
GstUtil.WriteLine(GstVerbosityLevel.Verbose, String.Format(
"Calling extendSuffixes() for word #{0:d}, with endIndex = {1:d} ('{2:c}') and active suffix = {3:s}",
wordNum, endIndex, GetWordChar(wordNum, endIndex), active.ToString()));
extendSuffixes(ref active, endIndex, wordNum);
}
if (doConsoleVerbose)
{
string logStr = String.Format("Done adding word #{0:d} (\"{1:s}\") to the suffix tree",
wordNum, wordDict[wordNum]);
GstUtil.WriteLine(GstVerbosityLevel.Verbose, logStr);
Console.WriteLine(logStr);
Console.WriteLine(this.ToString());
}
return(true);
}
