// Create and add, return new type (must not exist)
// Note: heading must have IsTuple=false to preserve order
public static DataTypeUser Get(string name, DataColumn[] columns)
{
var old = Find(name);
if (old != null && columns.SequenceEqual(old.Heading.Columns))
{
return(old);
}
Logger.Assert(!_usertypes.ContainsKey(name), name);
var flags = columns.Any(c => c.DataType.IsOrdered) ? TypeFlags.Ordered : TypeFlags.None;
var dt = DataTypeUser.Create(name, DataHeading.Create(columns, false), // preserve column order
flags | TypeFlags.Variable | TypeFlags.Generated | TypeFlags.HasName | TypeFlags.HasHeading);
_usertypes[name] = dt;
return(dt);
}
