public TagSegment GetFirstTagOnSegment(TextTagsState state)
{
int? openedIndex, closedIndex;
TagName?tagName;
while (true)
{
openedIndex = GetIndexTagBracket(state, IsOpenedTag, null, false);
if (!openedIndex.HasValue)
{
return(null);
}
state = state.ChangeSegment(openedIndex.Value, state.End);
tagName = GetTagName(state, IsOpenedTag);
var indexInTag = openedIndex.Value + Tags.GetMd(tagName.Value).Length;
if (indexInTag > state.End)
{
return(null);
}
state = state.ChangeSegment(indexInTag, state.End);
closedIndex = GetIndexTagBracket(state, IsClosedTag, tagName, true);
if (!closedIndex.HasValue || IsEmptyInsideTag(closedIndex, openedIndex, tagName))
{
continue;
}
break;
}
return(new TagSegment(tagName.Value, openedIndex.Value, closedIndex.Value));
}
private IEnumerable <TagSegment> GetAllTags(TextTagsState state)
{
var nextStates = new Stack <TextTagsState>();
for (var index = 0; index < state.Text.Length; index++)
{
var tag = finder.GetFirstTagOnSegment(state);
if (tag == null)
{
if (nextStates.Count == 0)
{
break;
}
index = nextStates.Peek().Start - 1;
state = nextStates.Pop();
continue;
}
yield return(tag);
var newStart = tag.CloseIndex + Tags.GetMd(tag.TagName).Length;
if (newStart < state.End)
{
nextStates.Push(state.ChangeSegment(newStart, state.End));
}
index = tag.OpenIndex + Tags.GetMd(tag.TagName).Length;
if (index <= state.End - 1)
{
state = state.SwitchTag(tag.TagName).ChangeSegment(index, tag.CloseIndex - 1);
}
index -= 1;
}
}
private int?GetIndexTagBracket(
TextTagsState state,
Func <TagName, TextTagsState, bool> condition,
TagName?expectedTagName,
bool isEqual)
{
return(Enumerable
.Range(state.Start, state.End - state.Start + 1)
.Cast <int?>()
.FirstOrDefault(i =>
Equals(GetTagName(state.ChangeSegment(i.Value, state.End), condition), expectedTagName) == isEqual));
}