// Create a new User type for a particular heading
public static DataTypeUser Create(string name, DataHeading heading, TypeFlags flags, ConvertDelegate converter = null, DefaultDelegate defaulter = null)
{
var dt = new DataTypeUser {
Name = name,
Heading = heading,
Flags = flags,
};
dt.NativeType = TypeMaker.CreateType(dt);
return(dt);
}
static public UserValue Create(TypedValue[] value, DataTypeUser datatype)
{
if (datatype.Name == "date")
{
return(Builtin.DateValue.Create(value[0] as TimeValue));
}
var ret = new UserValue {
Value = value, _datatype = datatype
};
ret._hashcode = ret.CalcHashCode();
return(ret);
}
// 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);
}
// construct a type from a base name, optional heading and optional user type name
public static DataType Derive(DataType basetype, DataHeading heading, string username)
{
if (basetype == DataTypes.Table)
{
return(DataTypeRelation.Get(heading));
}
if (basetype == DataTypes.Row)
{
return(DataTypeTuple.Get(heading));
}
if (basetype == DataTypes.User)
{
return(DataTypeUser.Get(username, heading.Columns));
}
return(basetype);
}
public UserValue UserSelector(TextValue typename, TypedValue[] valargs)
{
var usertype = DataTypeUser.Find(typename.Value);
return(usertype.CreateValue(valargs));
}
static DateValue()
{
// FIX: better to have a lookup for this
StaticDatatype = DataTypeUser.Get("date", new DataColumn[] { DataColumn.Create("super", DataTypes.Time) });
DataTypes.TypeDict[typeof(DateValue)] = StaticDatatype;
}
// Add a user type, just so it will get persisted
public void AddUserType(string name, DataTypeUser datatype, EntryFlags flags)
{
GlobalVars.AddEntry(name, datatype, EntryKinds.Type, flags);
}