private IEnumerable <object> LoopRel(IEnumerable <string> tokens, Func <string, string, string, object> map)
{
var enume = tokens.GetEnumerator();
var window = new List <string>(3);
var anyMore = true;
while (anyMore)
{
while (window.Count < 3 && (anyMore = enume.MoveNext()))
{
if (IsGroup(enume.Current) || OperChecker.IsLogOper(enume.Current))
{
if (window.Count != 0)
{
throw new Exception("Invalid logic expression");
}
yield return(enume.Current);
continue;
}
window.Add(enume.Current);
}
if (window.Count == 3)
{
yield return(map(window[0], window[1], window[2]));
}
else
{
foreach (var token in window)
{
yield return(token);
}
}
window.Clear();
}
}
