In such a case, the entire set of procedures can be viewed as a type; still there is currently no programming language yet that allows a user-defined type
with members of procedures.)
In C#, a struct is a simple user-defined type
, a lightweight alternative that is quite different from a class.
According to ODMG-97 [Cattel 1997], properties are referred to as attributes, when typed by an atomic type (such as string or integer) or relationships when typed by a user-defined type
. Furthermore, properties can be typed with collection types, such as sets, bags, or lists, that correspond to multivalued attributes and one-to-many relationships.
Clusters can be formed in a heuristic manner by grouping together: (i) a taxonomy of types that are reachable from some user-defined type
in inheritance lattice by following the is-a arcs in reverse order.
He covers getting started with your development environment, basic data types and operators, functions, flow of control, working with multiple files, unit testing, using C++ classes, user-defined types
, and a wide variety of other related subjects.
The same applies to code and feature sets such as full-text search, user-defined types
, change data capture, replication, and so forth.
An important and powerful generalization results from allowing user-defined types
wherever the primitive types can occur.
The classes from the conceptual model, which need to be made persistent by a StorageMechanism, which in this case is the ORDBMS, are mapped onto user-defined types
and corresponding typed tables.
Other languages do not support user-defined types
, or do so in a way that is not checked by the compiler.
In Ada 83, user-defined types
are always "specific" types, and when used as a formal parameter type, the actual parameter must have exactly the same type.
This article gives an overview of some of the extensions we have developed for Starburst to support hierarchies of user-defined types
and functions, large unstructured and structured complex objects, and user-defined rules to respond to changes in the database.