// Rule 1: Try to find matching edge for the parent node.
private ExtensionResult extendSuffixByRuleOne(
ref StSuffix active, ref StNode parentNode, int endIndex)
{
if (active.IsExplicit)
{
StEdge edge = active.OriginNode.GetChildEdge(text[endIndex]);
if (edge != null && edge.IsSet())
{
return(ExtensionResult.Done);
}
}
else // active suffix is implicit
{
StEdge edge = active.OriginNode.GetChildEdge(text[active.BeginIndex]);
int span = active.EndIndex - active.BeginIndex;
if (text[edge.BeginIndex + span + 1] == text[endIndex])
{
return(ExtensionResult.Done);
}
StUtil.WriteLine(StVerbosityLevel.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);
}
// Rule 2: Create a new edge and add it to the tree at the parent's position.
// Part of this is inserting the new edge into the hash table,
// and creating a suffix link to the new node from the last one visited.
private void extendSuffixByRuleTwo(
ref StSuffix active, StNode parentNode, ref StNode prevParentNode, int endIndex)
{
StEdge newEdge = new StEdge(this, parentNode, endIndex, this.text.Length - 1);
newEdge.Add();
StUtil.WriteLine(StVerbosityLevel.Verbose, String.Format(
" Rule #2: New edge E{0:d} (\"{1:s}\") connects N{2:d} (old parent) to N{3:d} (new child)",
newEdge.Id,
newEdge.GetText(),
newEdge.ParentNode.Id,
newEdge.ChildNode.Id
));
setSuffixLink(prevParentNode, parentNode);
prevParentNode = parentNode;
}
public StNode Split(StSuffix s)
{
Remove();
StEdge newEdge = new StEdge(tree, s.OriginNode, BeginIndex, BeginIndex + s.Span);
newEdge.Add();
newEdge.ChildNode.SuffixNode = s.OriginNode;
BeginIndex += s.Span + 1;
ParentNode = newEdge.ChildNode;
Add();
StUtil.WriteLine(StVerbosityLevel.Normal, String.Format(
" Split E{0:d} into E{1:d} + E{0:d} = \"{2:s}\" + \"{3:s}\"",
Id, newEdge.Id,
newEdge.GetText(),
this.GetText()
));
return(newEdge.ChildNode);
}
public StNode Split(StSuffix s)
{
Remove();
StEdge newEdge = new StEdge(tree, s.OriginNode, BeginIndex, BeginIndex + s.Span);
newEdge.Add();
newEdge.ChildNode.SuffixNode = s.OriginNode;
BeginIndex += s.Span + 1;
ParentNode = newEdge.ChildNode;
Add();
StUtil.WriteLine(StVerbosityLevel.Normal, String.Format(
" Split E{0:d} into E{1:d} + E{0:d} = \"{2:s}\" + \"{3:s}\"",
Id, newEdge.Id,
newEdge.GetText(),
this.GetText()
));
return newEdge.ChildNode;
}
// Rule 2: Create a new edge and add it to the tree at the parent's position.
// Part of this is inserting the new edge into the hash table,
// and creating a suffix link to the new node from the last one visited.
private void extendSuffixByRuleTwo(
ref StSuffix active, StNode parentNode, ref StNode prevParentNode, int endIndex)
{
StEdge newEdge = new StEdge(this, parentNode, endIndex, this.text.Length - 1);
newEdge.Add();
StUtil.WriteLine(StVerbosityLevel.Verbose, String.Format(
" Rule #2: New edge E{0:d} (\"{1:s}\") connects N{2:d} (old parent) to N{3:d} (new child)",
newEdge.Id,
newEdge.GetText(),
newEdge.ParentNode.Id,
newEdge.ChildNode.Id
));
setSuffixLink(prevParentNode, parentNode);
prevParentNode = parentNode;
}