public void Execute(SourceStack stack, TStoreProcessor processor, string token)
{
Match m = regex.Match(token);
if (!m.Success) {
Console.WriteLine("syntax error in Where()");
Environment.Exit(0);
}
string clause = m.Groups["c"].ToString().Trim();
RecordSource source = stack.Pop();
source = processor.SelectFilter(source, clause);
stack.Push(source);
}
