test.cs

private static List<BlockInfo> FindMergeBlocks(string input)
{
	const string pattern = @"\{\{(#foreach\s+\w+|\s*\/foreach\s+\w+)\}\}";
	var matches = new List<BlockInfo>();
	var stack = new Stack<Match>();

	foreach (Match match in Regex.Matches(input, pattern))
	{
		if (match.Value.StartsWith("{{#foreach"))
		{
			stack.Push(match);
		}
		else if (match.Value.StartsWith("{{/foreach") && stack.Count > 0)
		{
			var startMatch = stack.Pop();
			var startVar = ExtractVariableName(startMatch.Value);
			var endVar = ExtractVariableName(match.Value);

			if (startVar == endVar)
			{
				matches.Add(new BlockInfo
				{
					StartIndex = startMatch.Index + 1,
					EndIndex = match.Index + 1 + match.Length,
					BlockName = startVar
				});
			}
		}
	}

	matches.Sort((x, y) => x.StartIndex.CompareTo(y.StartIndex));

	return matches;
}