private bool TryFindFirstTag(int begin, int end, TreeNode parentNode, out TreeNode node, out Token token)
{
node = new TreeNode();
token = new Token();
var currentPos = begin;
while (currentPos < end)
{
if (TokenReader.TryParseDoubleUnderlineTag(_input, currentPos, end, out token))
{
if (!parentNode.IsRoot && parentNode.Type == NodeType.SingleUnderlineTag)
{
currentPos = token.Position + token.Length;
continue;
}
if (TokenReader.IsNumberWithUnderlines(_input, token.Position, token.Position + token.Length))
{
currentPos = token.Position + token.Length;
continue;
}
node.Type = NodeType.DoubleUnderlineTag;
return(true);
}
if (TokenReader.TryParseSingleUnderlineTag(_input, currentPos, end, out token))
{
if (TokenReader.IsNumberWithUnderlines(_input, token.Position, token.Position + token.Length))
{
currentPos = token.Position + token.Length;
continue;
}
node.Type = NodeType.SingleUnderlineTag;
return(true);
}
currentPos++;
}
return(false);
}