public List <TagToken> ParseLine(string line)
{
var result = new List <TagToken>();
if (line == null)
{
return(result);
}
var tagTokenStack = new Stack <TagToken>();
var index = 0;
while (index < line.Length)
{
var currentTag = tags.FirstOrDefault(tag => IsSuitableTag(tag, line, index));
if (currentTag == null)
{
index++;
continue;
}
if (DoubleTagValidator.IsPossibleOpeningTag(line, index, currentTag))
{
var newOpeningTagToken = new TagToken(index, currentTag, currentTag.Opening, true);
tagTokenStack.Push(newOpeningTagToken);
}
else if (DoubleTagValidator.IsPossibleClosingTag(line, index, currentTag))
{
while (tagTokenStack.Count > 0 && tagTokenStack.Peek().Tag != currentTag)
{
tagTokenStack.Pop();
}
if (tagTokenStack.Count == 0)
{
index++;
continue;
}
var newOpeningTagToken = tagTokenStack.Pop();
var newClosingTagToken = new TagToken(index, currentTag, currentTag.Closing, false);
result.Add(newOpeningTagToken);
result.Add(newClosingTagToken);
}
index += currentTag.Opening.Length;
}
return(result);
}
private bool IsSuitableTag(IDoubleTag tag, string line, int index) => DoubleTagValidator.TagStartsFromPosition(line, index, tag.Opening) || DoubleTagValidator.TagStartsFromPosition(line, index, tag.Closing);