private void Error(string error, string line, int location)
{
// append the line for context
result.Append("\n");
result.Append("// ");
AppendSubstring(line, 0, true, line.Length, false);
result.Append("\n");
// append the location marker, and error description
result.Append("// ");
result.AppendSpaces(location);
result.Append("^ ");
result.Append(error);
result.Append("\n");
}
