static int MatchGroup(string text, int groupStartIndex, int endIndex, ICollection <QueryError> errors, out StringView sv, out Match match, out bool matched)
{
sv = text.GetStringView();
match = null;
if (groupStartIndex >= text.Length || text[groupStartIndex] != '(')
{
matched = false;
return(-1);
}
matched = true;
if (groupStartIndex < 0 || groupStartIndex >= text.Length)
{
errors.Add(new QueryError {
index = 0, reason = $"A group should have been found but index was {groupStartIndex}"
});
return(-1);
}
var parenthesisCounter = 1;
var groupEndIndex = groupStartIndex + 1;
for (; groupEndIndex < text.Length && parenthesisCounter > 0; ++groupEndIndex)
{
if (text[groupEndIndex] == '(')
{
++parenthesisCounter;
}
else if (text[groupEndIndex] == ')')
{
--parenthesisCounter;
}
}
// Because of the final ++groupEndIndex, decrement the index
--groupEndIndex;
var charConsumed = groupEndIndex - groupStartIndex + 1;
if (parenthesisCounter != 0)
{
errors.Add(new QueryError {
index = groupStartIndex, length = 1, reason = $"Unbalanced parentheses"
});
return(-1);
}
sv = text.GetStringView(groupStartIndex + 1, groupStartIndex + charConsumed - 1);
if (sv.IsNullOrWhiteSpace())
{
errors.Add(new QueryError {
index = groupStartIndex, length = charConsumed, reason = $"Empty group"
});
return(-1);
}
return(charConsumed);
}
