public TreePatternParser(TreePatternLexer tokenizer, TreeWizard wizard, ITreeAdaptor adaptor)
{
this.tokenizer = tokenizer;
this.wizard = wizard;
this.adaptor = adaptor;
ttype = tokenizer.NextToken(); // kickstart
}
public virtual object ParseTree()
{
if (ttype != TreePatternLexer.Begin)
{
throw new InvalidOperationException("No beginning.");
}
ttype = tokenizer.NextToken();
object root = ParseNode();
if (root == null)
{
return(null);
}
while (ttype == TreePatternLexer.Begin ||
ttype == TreePatternLexer.Id ||
ttype == TreePatternLexer.Percent ||
ttype == TreePatternLexer.Dot)
{
if (ttype == TreePatternLexer.Begin)
{
object subtree = ParseTree();
adaptor.AddChild(root, subtree);
}
else
{
object child = ParseNode();
if (child == null)
{
return(null);
}
adaptor.AddChild(root, child);
}
}
if (ttype != TreePatternLexer.End)
{
throw new InvalidOperationException("No end.");
}
ttype = tokenizer.NextToken();
return(root);
}